116 PCM MINUTES MAIL LIST - wrpcwrpc.gov.in/pcm/116pcm_minute.pdfAt 00:05 Hrs, due to operation of LBB protection of Bus-III at Korba Generating station, all the elements connected

116 PCM MINUTES MAIL LIST

1) Chief Engineer (LD), MSETCL, Kalwa. 2) Chief Engr. (Trans O&M), MSETCL, Bandra. 3) S.E. (T&C), MSETCL, Aurangabad. 4) S.E (T&C), MSETCL, Pune. 5) S.E. (T&C), MSETCL, Nagpur. 6) S.E.(T&C), MSETCL, Nasik Road. 7) S.E.(T&C), MSETCL, Vashi. 8) S.E.(Gen.Tstg), MSPGCL,Eklahre, Nasik. 9) S.E. (Task Force), MSPGCL, Nagpur.

10) S.E.(TCC), MSETCL, Karad. 11) Chief Engineer (Gen), GSECL, H.O. Baroda. 12) Addl. C.E.(Testing), GETCO, Baroda. 13) Chief Engineer(LD), MPPTCL, Jabalpur. 14) E.D. (T&C),MPPTCL, Jabalpur. 15) Addl.C.E., MPPGCL, Jabalpur. 16) Chief Engineer (LD), CSPTCL, Bhilai. 17) C.E. (T&C), CSEB, Raipur. 18) EE (T) , CSPGCL,Raipur. 19) S.E.(T&C), CSPTCL, Bhilai. 20) S.E.(T&C), CSPTCL, Raipur. 21) E.E.(T&C), CSPTCL, Bhilai. 22) EE, Division VIII(MRT),Elect. Dept; Goa. 23) Supdt.Engr., Electricity Dept., DNH, Silvasa. 24) Executive Engr., Electricity Dept. DD. Daman. 25) D.G.M.(O.S. ),N.T.P.C., Mumbai, 26) D.G.M.(EM), KSTPS, NTPC, Korba. 27) DGM (EMD), VSTPS, NTPC, Vindhyachal. 28) DGM (EM-I), NTPC, SIPAT . 29) AGM(O&M), KGPP, Adityanagar, Surat. 30) Sr.Supdt. (EM), Gandhar, NTPC. 31) DGM (O.S.), WRLDC, Mumbai. 32) DGM, WRTS-I, POWERGRID, Nagpur. 33) Addl General Manager, WRTS-II, POWERGRID, Baroda. 34) SME (E), TAPS-3&4,Tarapur. 35) Maintenance Superintendant, TAPS –1 & 2,Tarapur. 36) SME(E), NPCIL , Kakrapara. 37) GM(Maint.). TORRENT Power., Ahmedabad. 38) AGM (ET&A),TPC, Trombay. 39) Dy.Gen. Manager, Dahanu TPS,Dahanu. 40) Vice President, Reliance Energy, Mumbai. 41) GM (Electrical), JPL, Raigarh. 42) AGM(OS), NSPCL, New Delhi . 43) Vice President(O&M), APL, Ahmedabad. 44) GM, RGPPL, Anjanwel, Guhagar, Ratnagiri, 45) GM, JSW Energy Ltd., Jindal Mansion, Mumbai. 46) GM, CGPL, Mundra. 47) Director (G M Division), CEA, New Delhi.

1 Minutes of 116th Protection Committee of WRPC

MINUTE OF 116th PROTECTION COMMITTEE MEETING OF WRPC HELD ON

30/31.01.2013 AT NAGPUR

The 116th Protection Committee Meeting of WRPC was held on 30/31.01.2013 at Nagpur.

The list of participants is placed at Annexure -I.

Shri Bharat Bhusan,ED, WRTS-I, PGCIL, Nagpur welcomed all the members and

participants and highlighted the progress of Powergrid , WRTS-I at a glance. He stated that

availability of transmission system of PGCIL is around 99.97 %. Even the nonavailability of

0.03 % can cause havoc in the grid. He stated that grid is becoming more & more complex

and sensitive and emphasized that while designing the protection system we should take a

Region as a single entity.

Shri S. D. Taksande, Member Secretary (I/C), WRPC, welcomed all the members and the

participants of the 116th Protection sub-Committee Meeting. He stated that he had attended

the meeting of task force formed by MOP, who discussed islanding schemes philosophies

in general . He briefed about the discussions held in the meeting and intimated that earlier

islanding scheme’s philosophy was subjective and in the hands of the utilities but now

standard guidelines would emerge. He also intimated the task force meeting’s decision to

form bigger islanding schemes and avoid the small islands. He also emphasized role of

WAMS technology in protection/defense of the grid. He thanked PGCIL, WRTS-I for

making excellent arrangements for stay and transport of the participants and conduct of

meeting.

Member Secretary (I/C) then requested Shri M. M. Dhakate, SE(Protection), WRPC to take

the agenda items for discussion in seriatim.

The agenda items were taken up for discussions.

ITEM NO.1: CONFIRMATION OF MINUTES OF 115TH PROTECTION

COMMITTEE MEETING.

SE(Protection), WRPC stated that the minutes of 115th PCM, held on 06/07.09.2012 at Pune,

were circulated vide WRPC letter No. Prot./115 PCM/2012/WRPC-9458 dated 26th Sept.

2012. We have not received any comment on any item of minutes and therefore the minutes

of 115th Protection Committee were confirmed without any modifications.


ITEM NO.2: SYSTEM DISTURBANCES

2.1 (i) Occurrence at Sipat STPS on 14.09.2012

SE(Protection), WRPC stated that at 1852 hrs of 14.09.12 all the running units at Sipat tripped,

resulting into a loss of around 2000 MW generation alongwith lines emanating from Sipat. Frequency

dipped by 0.814 Hz( i.e. from 49.911 hz to 49.097 Hz). The df/dt rate reported from Raipur PMU was

- 0.15 Hz/sec. There was no loss of load but such huge quantum of generation loss and tripping of

765 kV lines would have resulted in a catastrophic failure. In order to avoid such occurrence at Sipat,

it was felt necessary to analyze this occurrence in detail and come out with recommendations.

Accordingly, a meeting was held on 21.09.2012 at NTPC office, Mumbai. The occurrence was

discussed thread bare and following recommendations were evolved. The complete record notes of

discussion have already been circulated to all and are available on website of WRPC.

The recommendations and present status as given by NTPC representative during the meeting

is as follows :

a) Committee recommended that in the event of using line reactor as bus reactor PLCC should be

switched off at both ends. – Practice now being adopted.

b) Committee however felt that had CSR been used, the stresses on the breaker could have been

minimized and saved the occurrence. Also, in the event of non-availability of CSR, frequent

switching of reactor as bus reactor should be minimized to reduce stress on breaker. – CSR on

Ranchi-1 installed and CSR installation in Ranchi-2 in progress

c) Committee recommended that the characteristics and timing of the back up E/F protection

should be changed to IDMT on both sides of ICTs.- Complied

d) Committee recommended that the timing delay of the 11 kV should be revised to 2-3 seconds

after necessary studies by NTPC.-Timer procurement in progress

Other issues & Recommendations (as suggested by GM, WRLDC)

1. Over voltage trip setting at Seoni end can be increased to 110%.- Complied

2. Manual control of backing down generation at JPL, Lanco etc.-Taken up by WRLDC

3. Raise generation in Maharashtra in Koyna area- Taken up by WRLDC

4. Proposal for one additional line from Sipat to Bilaspur pooling station- To be taken up in Standing Committee of WR

5. Automatic control through new SPS – To be discussed separately

Further, CE(LD), MPPTCL vide letter dated 18.09.2012 addressed to Executive Director

(O&M:Gen.), M.P. Power Generating Co. Ltd., Jabalpur have intimated that disturbance occurred


at Sipat STPS on 14.09.2012 which caused tripping of 400 KV lines at 765 KV sub-station, Seoni.

The 400 KV STP-Seoni line tripped from Seoni end only and after about 15 minutes, the breaker

was hand tripped at Sarni end as the same was not tripped at STPS. In the past also this line was

tripped at Seoni end only.

With regard to tripping of 400 kV Sarni – Seoni line at Seoni end only, the Committee concluded

that the PLCC equipments at Sarni end are very old and non working hence need to be replaced by

MPPGCL. MPPGCL representative told that bay equipments at Seoni belong to PGCIL hence the

PLCC equipment shall be replaced by PGCIL. PGCIL representative intimated that new PLCC

equipments have been installed by PGCIL at Seoni and Bhilai ends for 400kV Seoni-Bhilai line and

since the 400 kV Sarni-Seoni line belongs to MPPTCL, therefore PLCC equipments at Sarni &

Seoni ends should be provided by MPPTCL/MPPGCL.

In view of above, PGCIL-WR-II intimated that relevant provisions in the Central Electricity

Authority (Technical Standards for Connectivity to the Grid) Regulations, 2007(copy enclosed at

Annexure-2.1(i) could be referred for resolving the above disputes.

Committee felt that the issue may be resolved as per CEA/CERC regulations regarding

ownership/maintenance of communication equipments.

2.1 (ii) Occurrence at Korba(E) and Korba(Extn) on10.09.12

CSPGCL representative explained the occurrence as below :

At 17:34 Hrs, due to heavy flashover in R –Phase LA of the 220 kV Korba (E)-Korba(W) I/C

III while charging which led to collapsing of wave trap of same phase of the feeder and

snapping of the Jumper of 1P & 2P Bus of 220 kV Korba(E)-Korba(W) I/C I leading to

ground fault. The ground fault was sensed by all the generating unit and lines on Bus 1P and

2P as well as same was sensed by at 132 kV Korba(E) and Bango S/S. This led to tripping of

all the lines and feeders at 220 kV Korba (E), 220 kV Korba (E)-Extn,132 kV Korba (E) and

132 kV Bango S/S.

With the loss of generation of 560 MW, frequency dipped by 0.30 Hz( i.e. from 49.98 Hz to

49.68Hz). The df/dt rate reported from B’wati PMU was - 0.053 Hz/sec.

At 17:55 Hrs partial station supply was restored from 33 kV feeders. After that 220 kV 2P

Bus was charged from 220 kV Korba-Raigarh line and full station supply was restored. 220


kV 1P Bus was charged through 160 MVA Auto transformer I. With full restoration of 220

kV Bus at Korba (E), 220 kV Korba (E)-Balco-I & II was charged and Balco-CPP1-GT-4 got

connected with grid. At 19:52 hours Korba (E) Unit 4 was synchronized with the grid. Then

after Unit 1 and 5 was synchronized. During the restoration work, at 22:58 132 kV Champa-

Banari I & II lines tripped on Over current protection from Champa end which led to

insufficient evacuation path from Korba(E). Due to this Korba(E) system became unstable

and wide fluctuation of frequency was observed(50 to 54 Hz). This led to tripping of all the

feeders and 220 kV on Bus 1P of Korba(E). Again the restoration work started in the same

manner. The tripping details from Korba(E) is still awaited as DR/EL files were unavailable.

Committee felt that flashover of LA, collapse of wave trap and snapping of 1P & 2P Bus

of interconnector can not be related to each other and requested CSPTCL to submit

the detailed report and sequence of tripping along with DR/EL output files to

WRPC/WRLDC for complete analysis.

2.1 (iii) Occurrence at Korba, NTPC on 11.09.12

NTPC representative explained that occurrence as below :

At 00:05 Hrs, due to operation of LBB protection of Bus-III at Korba Generating station, all

the elements connected with the bus become dead. This lead to tripping of Unit-5 and 7 at

Korba NTPC and Unit 1 and 2 at BALCO. 400 kV Korba- Raipur IV line tripped on Rph-E

in Zone-1 distance protection. The fault was temporary in nature and auto reclosure operated

successfully. However LBB relay of Bus-III mal-operated, leading to tripping of all the

connecting elements on this bus. With the loss of generation of 1100 MW, frequency dipped

by 0.547 Hz (i.e. from 49.749 Hz to 49.202 Hz). The df/dt rate observed from Bhadrawati

PMU was 0.0592 Hz/sec.

NTPC representative further intimated that the LBB trip relay contact was in stuck up

condition and not getting resetted. The trip relay was replaced. Committee opined that

the maloperation of protection equipment is a serious threat to the reliability of the

system hence it was suggested that the quality inspection of the protection equipment

and their upgradation from time to time is required.

2.1 (iv) Occurrence at Bhilai on 30.10.12


CSPTCL representative explained the occurrence as below :

At 12:23 Hrs on 30th Oct’12, due to failure of CVT/CB/LA of 220KV BSP-feeder I at

400/220KV Bhilai (Khedamara) Sub-station, 220 kV main bus tripped on bus bar protection.

Due to this, all 220 kV feeders emanating from Bhilai (Khedamara) tripped along with

400/220 kV ICT I, II and III. 400 kV Bhilai – Seoni S/C and 400 KV Bhilai – Bhadrawati

S/C also tripped simultaneously. 220 kV S/s Bhilai, Thelkadih, Gurur, Barsoor and 132 kV

S/s of Bhilai, Ruabandha, Kurud, Rajnandgaon, Dongorgaon, Gunderdhehi, Balod,

Dallirajhara, Kanker, Jagdalpur and Dongargarh were affected due to the occurrence. The

220 kV Raipur – Bhilai line tripped in Zone-3.

CSPTCL representative further intimated that the CVT Top dome broke & started swinging

then thereby touching the other phase conductor resulting in Ph to Ph & E/F .

Committee felt that tripping of 220 kV Raipur – Bhilai line in Zone-3 was undesireable

and should have tripped in Zone-2. CSPTCL was requested to check up/test the DPS of

220 kV Raipur – Bhilai line. Tripping of 400 kV Bhilai – Seoni & and 400 KV Bhilai –

Bhadrawati was undesirable for fault in the 220kV system and therefore CSPTCL shall

test the DPS and check the DPS settings. Further CSPTCL shall also check the timing

of trippings from event logger and also carry out the diagnostic test of Bus-Bar / Bay

equipments regularly.

2.1 (v) Occurrence at Jindal on 14.09.12

JPL have intimated that on 14th Sept’ 12 at 19:15 Hrs both 400KV JPL (Tamnar) – Raipur

Line 1&2 tripped on Direct trip command received from Raipur end. Which lead to tripping

of all running 03 Units of 250MW (one unit no. 2 was under AOH). The tripping of all units

and lines resulted in Black-out in O.P. Jindal Thermal Power Plant. In detailed analysis, it is

found that direct trip command received at JPL due to hand trip operation at Raipur end for

both the lines and message was received from POSOCO vide fax no. LD/9/1176 dtd.

14.09.2012 that opening of 400 KV JPL – Raipur lines from Raipur end due to an occurrence

at Sipat Generating Station. The generation loss due to tripping of JPL Unit was 756 MW.

JPL.

This occurance is a part of occurance at Sipat on 14.09.2012 and was analysed

alongwith NTPC Sipat occurance.


2.2: System disturbances in GETCO/GSECL system.

2.2(i) Occurrences at CGPL in July 2012 and September 2012

CGPL :02.07.2012

At 05:53 hrs on 2nd July, 2012 there was an occurrence at 440 kV CGPL-Mundra S/S due to

earth fault which resulted in operation of Bus-Bar protection. Prior to the incident, Main Bus-

1 & 2 along with GT-10, GT-30, Limbdi circuit-I & II, Bhachau circuit- I & II along with

line reactor (Limbdi-1, Limbdi-2 and Jetpur-2) and bus reactor on CGPL-Mundra 400 kV S/S

were in service. The weather condition on the day was foggy. At 04:19 Hrs, 400 kV

Mundra-Limbdi II got tripped on earth fault in phase B. Later at 04:29 Hrs main Bus-II at

400kV tripped on bus-bar protection due to bus support insulator failure located in Y phase.

Main Bus I voltage dipped from 236 kV to 5.54 kV in Y phase. After that 400 kV Mundra-

Limbdi II was charged with main bus-I at 05:00 Hrs. It again tripped due to earth fault in Y

phase at 05:37 Hrs. Around 05:50 Hrs, 400 kV Mundra-Limbdi I also tripped on earth fault

in Y phase. At 05:53 Hrs, Main Bus - I of CGPL Mundra 400 kV S/S tripped on Bus-Bar

Protection due to blasting of CB in R Phase. This led to the tripping of all the lines from the

400 kV bus and Unit-10 which was generating 685 MW at the time of incident went out of

service on protection.

CGPL : 30.07.2012

At 06:06 Hrs, due to tripping of 400 kV CGPL- Limbdi-II on Y-B Phase fault, 220 kV

Network from Bhachau also got tripped on over current which led to separation of CGPL

Units along with Bhachau load from the rest of the grid. Earlier to the event, 400 kV CGPL-

Limbdi-I was out due to R Phase to earth fault and 400 kV Bhachau - Ranchorpura I & II

tripped at 06:04 hrs on Y phase to earth fault. With separation of CGPL from the grid, Unit

20 immediately tripped while unit 10 operated with Bhachau loads for 50 Min. 400kV

Bhachau-Ranchorpura II was charged at 06:57 Hrs but it tripped on Y phase to earth fault at

06:58 Hrs causing power swing and led to tripping of Unit 10.

400 kV CGPL-Limbdi I and II were continuously tripping due to line to ground fault which

was reasoned out to be due to flashover of insulators. At 05:26 Hrs 400 kV CGPL-Limbdi I

got tripped again on R-Phase to ground fault nad was not taken in service due to persisting

fault. At 05:45 Hrs 400 kV CGPL-Limbdi II got tripped on B-Phase to ground fault and was


taken in service at 06:02 Hrs. At 06:04 Hrs 400 kV Bhachau-Ranchorpura I & II tripped on

Y Phase to ground fault and the generation at CGPL was reduced to supply Bhachau ICT and

400 kV Limbdi line II.

At 06:08 Hrs 400 kV CGPL-Limbdi II got tripped due to Y-B Phase fault. This led to

tripping of 220 kV lines from Bhachau due to over loading and Unit 20 got tripped while

Unit 10 came on Bachhau Load. Frequency Change :Grid frequency dropped from 49.97 Hz

to 49.09 Hz due to sepeartion of CGPL units from the rest of the grid leading to generation

loss of 1491 MW. Raipur df/dt observed during the incident was -0.08 hz/sec .

Restoration : Restoration was started by 06:57 Hrs by charging 400 kV Bhachau-

Ranchorpora II line from Bhachau end .The line got tripped on yphase to ground fault and

the Unit 10 observed power swing leading to its tripping on reverse power protection .This

led to loss of Swicthyard supply at CGPL. At 07:10 Hrs switchgears were charged via 220

kV Nanikhakar supply and at 10:13 Hrs 400 kV switchyard was charged. Around 19:10 Hrs

unit were ready in rolling condition but due to higher eccentricity of shaft it was shutdown

for further investigation.

CGPL : 31.07.2012

At 04:32 Hrs, due to tripping of 400kV Bhachau S/S last tie breaker (only 400 kV Mundra-

Bhachau 1 & 2 was in service with only tie breaker at Bhachau end in service,400 kV

Bhachau-Vadavi 1 & 2 and CGPL-Limbdi 1 & 2 were not available), Unit -20 of CGPL

resulted in islanding mode operation with 57 MW Bachau load. Unit was then manually

tripped after 39 minutes of low load operation.

At 00:45 Hrs:CGPL Unit -10 was out of service and Unit -20 was running at 325 MW load.

Main bus 1 & 2 ,GT # 1 ,GT#20,400 kV CGPL-Bhachau 1 & 2 , 400 kV Bhachau-Limbdi 2

along with its L/R were in service.400 kV Bhachau-Limbdi 2 was out due to breaker

problem. At 00:47 Hrs:Bhachau-Limbdi 2 line tripped on zone 1 protectionin R-Phase fault.

This line was charged again at 01:09 Hrs but again it tripped at 01:28 Hrs .Further it was

once again charged at 03:02 Hrs but this time it trippedon zone 1 Protection in Y phase fault

at 03:54 Hrs. At: 04:32 Hrs: With only 400 kV CGPL- Bhachau 1 & 2 in service with only

one tie breaker at Bhachau (out of 4 Tie-breaker, 2 Nos. oftie were out due to problem in CT

and 3 breaker opened during 400 kV Bhachau-Vadavi 2Tripping), the tie breaker tripped

resulting in islanding of 400 kV Main Bus 1 of Bhachau islanded from the grid. This lead to


load throw off of 268 MW and Unit-20 came on 57 MW Bachau load.

With the loss of generation, frequency dipped by 0.243 Hz ( i.e. from 49.953 hz to 49.710

Hz).

GM, POSOCO, WRLDC vide letter dated 9.10.2012 referring to Item No. 4.2 of the 115th

PCM have quoted as below:

“GM, WRLDC stated that there was communication problem between operators of

CGPL and WRLDC as house loading intimated by CGPL was not understood by

WRLDC as islanding of the station of house loading has a different connotation.

After receiving the code from WRLDC, the line Bachhau-Ranchodpura-II was

successfully synchronized at Ranchodpura through synchroscope at 06:58 hrs of

30.07.2012 and after one minute i.e. 06:59 hrs, the line tripped on Y-ph fault

indication. Probably the fault on this line might have caused instability on CGPL

unit.

Further, the codes are issued by WRLDC only after concerned agencies are ready

after inturn confirming the same from their respective substations. On 30.07.2012,

the data of Bachhau was not available and code was issued only after readiness of

CPCC(Jabalpur) and GETCO. The Ranchodpura S/s and Bachhau S/s had to

communicate regarding synchronizing conditions and Ranchodpura S/s was well

aware of synchronizing parameters as it was carrying out synchronization through

synchroscope. Also, as said earlier, the line was successfully charged for one minute.

CGPL : 18.09.2012

At 14:38 Hrs, due to spurious trip signal generated from the system turbine protection

scheme of Unit-10 at CGPL tripped. At 14:38:09 Hrs due to spurious trip signal from turbine

protection scheme, generator circuit breaker opened and lockout relay operated, leading to

tripping of Unit-1o of CGPL.

With the loss of generation ,frequency dipped by 0.53 Hz ( i.e. from 49.77 hz to 49.24

Hz).The df/dt reported from Raipur PMU was - 0.035 Hz/sec. The tripping was initiated by

the malfunctioning of turbine protection scheme.


CGPL : 22.09.2012

At 17:04 Hrs, due to tripping of major auxiliaries on under-voltage, leading to boiler tripping

on low furnace pressure. This lead to tripping of CGPLUnit-10. At 17:04:52 Hrs due to

Under Voltage relay operation of FD Fan auxiliary of CGPL Unit-10, other major auxiliary

tripped which led to tripping of boiler on low furnace pressure.Unit-10 turbine got tripped on

boiler protection eventually leadingto lockout relay operation of Unit-10.

With the loss of generation ,frequency dipped by 0.363 Hz ( i.e. from 50.228 Hz to 49.865

Hz).The df/dt reported from Raipur PMU was - 0.033 Hz/sec.

It was found that the micro SCADA has generated the signal to open the the 11 kV bus

breaker which was supplying the 6.6 kV Bus. As the 11 kV bus became dead leading to

under voltage protection operation of auxilaries connected on 6.6 kV. So the mal-operation

of communication system of Micro SCADA for auxilary supply of Unit-10 led to tripping of

Unit-10.

Committee felt that to minimize the trippings due to insulator flashover in prevailing

weather conditions, Silicon coated insulators should be provided in the switch yard.

Also, thermo vision scanning and regular cleaning of insulators can minimize the

occurrence. CGPL representative stated that the 40 % of insulator Silicon Coating

works have been completed.

The committee further requested CGPL to expedite the works and propose for availing

outages on suitable dates for carrying out the Silicon coating works on remaining

insulators to avoid the occurrences.

2.2(ii) Occurrence at Kakrapar APS on 12.06.12

NPCIL representative explained the occurrence as below :

On 12.06.12 at 19:47 hrs 220 kV bus bar#2 tripped on bus bar differential protection.

Switchyard survey was carried out just after the incident. At the extreme end (13th bay) of

the main Bus-II a section of R phase busbar was found bent. Bus post insulator was found in

snapped condition near R phase bus post insulator structure and its base part was still intact

on structure. Some of the broken insulator pieces were found lying on the ground near

support structure and on visual examination these were giving the impression of freshly


broken porcelain. Further, visual examination of sheared BPI base indicated that 40 % area

appear to be fresh one and remaining area having dull appearance giving impression of

existence of internal crack since long period.

Committee felt that internal hair line cracks might have developed in base area of

insulator which might have made the structure weak to withstand the heavy wind

pressure. The weak portion of the insulator got snapped and sheared off from its base

due to heavy wind forces during stormy conditions. NPCIL, KAPS was advised to

monitor closely the strength of PBI and other EHV equipments during routine

inspections.

2.2(iii) Occurrence at APL Mundra in June 2012

APL Mundra :29.06.2012

At 4:52 hrs on 29.06.2012 Sami-Adani circuit I & II tripped on zone –I distance protection ,

SPS stage-II at Adani operated leading to tripping of Unit-5. This led to voltage dip which

caused the tripping of coal feeders of Unit-3 & 4 on under voltage. With the tripping of coal

feeders, critical flame loss was occurred and subsequently MFT acted which led to tripping

of APL Unit-3 & 4. Undervoltage was sensed in the system for more than 300 ms.

Frequency change was observed from 49.58 to 48.98 Hz.

APL Mundra :30.06.2012

At 01:22 hrs on 30.06.2012 due to tripping of APL-Sami-Dehgam-1 on zone-1 distance

protection, stage-II of SPS at adani operated leading to tripping of Unit-4. This led to

overloading of APL-Sami-Dehgam-II which resulted in tripping of Unit-5 due to operation of

Stage-III of SPS at Adani. Frequency change was observed from 49.52 to 49.10 Hz.

Committee observed that report submitted by WRLDC was not adequate to analyse the

occurance and M/s APL may submit detailed report.

2.2(iv) Occurrence at 220 kV Vapi(PG) and 220 kV Bhilad on 23.11.2012

GETCO representative explained the occurrence as below:

On 23.11.2012 at Vapi (PG) s/s bay outage of ICT-I main bay was going on for AMP works

(DCRM and timing testing of CB). At 15:17:19 hrs at Vapi (PG) s/s 220 kV Vapi (PG)-


Magarwada –I line (connected to 220 kV bus-1 which was carring load of 80 MW) LBB

relay (make ABB) operated leading to the tripping of 220 kV Bus-I tripping all the feeders

connected to Bus-I including ICT-I. This resulted in over-loading on 400/220 kV Vapi(PG)

ICT-II (Bus-II) to 390 MW as this was the only source left. This over loading led to the

operation of HV back up over current protection of ICT-II leading to its tripping. With the

tripping of ICT-II power source for Bus-II connected 220 kV feeders for DD/DNH got

transferred to 220 kV Bhiad s/s with power being fed from 220 kV 220 kV TAPS-Bhilad,

Navsari-Bhilad and Vapi(Guj)-Bhilad lines. It resulted in overloading of all the 220 kV

feeders connected to Bhiad s/s. 220 kV Bhiad-Vapi(Guj) and 220 kV Bhilad-Navsari tripped

on over current protection along with 220 kV Vapi(PG) –Bhilad-I & III. This led to loss of

DD and DNH load from the grid and zero power at Vapi(PG) s/s. 220 kV Vapi(PG) –

Magarwada-II and Vapi(PG)-Kharadpada-I lines remained floating due to loss of supply.

Subsequently, R phase dropper jumper of 220 kV TAPS-Bhilad line detached from clamp

due to overheating. The 220 kV breaker of TAPS-Bhilad line was manually tripped leading

to zero power at Bhilad s/s.

For investigating cause of undesired operation of LBB relay of 220 kV Vapi(PG)-Magarwada

–I , the LBB relay was tested and was found in order. It was suspected to DC leakage might

have occurred which led to initiation signal to LBB relay. All the possible sources of DC

leakage were traced and rectified at site.

Committee felt that the operation of LBB protection was undesirable and DC leakages

should be monitored contineously. The other trippings due to overloadings were in

order.

2.3: System disturbances in MPPTCL/MPPGCL system.

2.3(i) Occurrence at Amarkantak TPS 28.06.2012.

At 23:32 Hrs on 28.06.2012 there was an occurrence at Amarkantak TPS generating station

and 220/132 kV S/s due to CVT burst in R phase of the traction feeder no. 1. Due to bursting

of CVT, its flame directly created the bus fault. This led to tripping of all the lines connected

to the bus except 132 kV Amarkantak-shadol and Amarkantak-Rajmilan-II. With the

tripping of evacuation lines from Amarkantak S/s ATPS unit 3, 4 and 5 tripped. Due to this


the 220 kV bus and 132 kV bus at Amarkantak S/s became dead. He further informed that

Bus bar protection was out of service due to problem in B/B protection scheme.

Committee observed that tripping of lines from remote ends in the absence of Busbar

protection was in order. However, Committee recommended that the Busbar protection

should be put in service at the earliest.

2.3(ii) Occurence at Omkareshwar on 28.08.2012

NHDC representative explained the occurrence as below:

On dated 28.08.2012 at 13:05 hrs., MP system was running with new grid at freq. 50.17Hz

with available thermal generation 1252MW and hydel generation 1747MW. MP was drawing

733MW against ISGS schedule of 815MW. Generation at OSP was 364MW. At around

13.10Hrs., it was observed that all seven running machines at OSP got tripped

simultaneously. Further it was reported by OSP that 220KV OSP- Khandwa line tripped from

both ends on Y phase to Earth fault indication on zone-1. As indicated in DR/SER print, huge

fault current was fed by OSP generators and Khandwa PG (ICTs). As per SER timings ,

220KV OSP-Khandwa appears have been tripped at 13:10:05 hrs., hence fault cleared,

however running units started tripping from 13:11:45 hrs except units no. 02. DR/SER report

enclosed at Annexure-2.3(ii).

Event in line (OSP-Khandwa) Line Length: 97.543 KM

The OSP-khandwa Line got tripped at 13:10:05 Hrs as recorded at REL 511 Relay on Y-

phase to earth fault at 1.1 km from OSP end, Zone-1 trip, General trip, Group A/B relay,

operated. At Khandwa end line tripped on Y-phase to 2nd stage earth fault at 69.9km from

Khandwa end on Zone-1 trip, General trip, Group A/B relay operated. The disturbance

records of REL 511 relay indicates that the fault current was in the range on 13 kA during the

fault and it was cleared in around 55ms. All the 7 nos. running generating units at OSP also

got tripped during the occurrence of the fault simultaneously along with the faulty line. The

timing at SOE installed with SCADA was recorded 13:11:45 hrs. The fault indications

appeared at generating unit is GT over current resulting in Class C Tripping of the unit. The

data signifies that the fault get cleared instantaneously. The REL511 of line-5 and SCADA at

OSP is not time synchronized, due to which the time of fault clearing and the tripping of

generating units seems to be mismatched. Whereas the SCADA report at OSP and WRLDC


shows the simultaneous tripping. Time Synchronization with GPS is done on weekly basis

manually till further arrangements have been made.

Committee observed that tripping of generating units on over current protection was

undesirable since the fault was cleared within Zone-1 timings. The over current relays

of the GTs should be tested and the settings should be checked for co-ordination.

Further DRs should be time synchronised with GPS at regular intervals(weekly).

2.3(iii) Occurrence at Sarni STPS on 5.09.2012

MPPGCL representative explained the occurrence as below :

On Dt.05.09.2012 at 10.13 hours the 220 KV Bus-1 tripped on Zone –I on R & Y Phase due

to inrush current while charging 500MVA ICT. The Bus bar protection in turn tripped all the

Generators, Feeders and Transformers connected to 220kV Bus-I. Within few seconds all the

Generators, Feeders and Transformers connected to 220kV Bus-II also tripped. Thus both the

220 kV Buses at STPS become dead.

MPPGCL representative further intimated that ABB Engineers were called for testing and

recalibration of the Bus Bar Protection. It has been advised by ABB to provide Numerical

Relays for DPRs of Feeders and Bus Bar Protections, in line with WRPC recommendations.

MPPGCL representative intimated that ABB have checked the static bus bar relay schemes

and many diodes of measuring units were found shorted. M/s ABB have replaced the faulty

diodes and system was normal.

Committee felt that B/B protn. (Zone-I & II) should not have operated due to inrush

current of the 500MVA 400/220 kV ICT and therefore B/B protection might have mal-

operated due to failure of diodes.

2.3(iv) Occurrence at Tons HPS on 7.10.2012


On dated 07.10.2012 at 21.35 Hrs, MP System was running at frequency 50.15 Hz NEW

grid. At Tons HPS three machines were running on full load. At around 21.40 Hrs, it was

observed that all running machines got tripped and all outgoing 220 KV lines also tripped.

Further it was informed by Tons HPS that B-Phase jumper between breaker and line isolator

of 220 KV Tons-Rewa Ckt. No.l snapped at Tons end. Fault on 220 KV Tons-Rewa I line


has taken 375.8 ms to clear the fault on Zone-4 and 220 KV Tons-Satna & 220 KV Tons-

Kotar also tripped on Zone-4 at Tons end. 220 KV Tons-Satna & Tons-Kotar lines tripped at

Tons. Hence all three lines tripped from Tons end and supply failed on 220 KV bus.

Thereafter all three running machines tripped on over-speed. Line protections settings at

Tons, Satna, Rewa & Kotar needs to be checked to avoid such type of unwanted trippings.

The B/B protn. is faulty & out of service. Proposal for procurement of Digital Bus Bar

Protection scheme is being initiated by site . The Z-4 in reverse direction has been enabled on

all the feeders emanating from Tons HPS in the absence of B/B protn. with a time delay of

100 ms.

Committee observed that trippings in Z4 (reverse direction) was in order, in the absence

of B/B Protn. and recommended that the BB Protection scheme should be provided at

the earliest. MPPGCL representative informed that Numerical BB protection scheme is

under procurement stage and would be commissioned shorthly.

2.3(v) Occurrence at 220kV Burwaha S/s on 17.10.2012

MPPTCL representative explained the occurrence as below :

On 17.10.2012, MP System was running normal with NEW grid at frequency 49.94 Hz. At

220 KV Burwaha S/s, shut down was given on 3x40 MVA for maintenance work and 160

MVA X-mer was on load. Loading on all 220 KV lines emanating from Burwaha sub-station

was normal. At around 12.54 Hrs, B-phase tension string towards 160 MVA X-mer has

failed and this has created bus fault on 220 KV Main bus. All 220 KV lines emanating from

Burwana 220 KV sub-station tripped from remote end on Zone-II and total supply failed on

220 KV Bus. Load from 132 KV bus was managed and there was no any interruption in the

adjoining sub-station. MPPTCL representative informed that B/B protn. scheme is not

provided.

Committee observed that tripping of lines from remote end in Z-II in absence of B/B

protn. scheme was in order and requested to MPPTCL to install B/B protn. scheme at

the earliest.

2.3(vi)A Overvoltage at ISP & Birsinghpur (to check whether item to be included in

Any other Item)


CE(LD), MPPTCL intimated that over voltages are observed on the Sarni and ISP corridors

therefore overvoltage conditions need to be addressed. He further informed that earlier the

O/V stage I settings adopted were 110% of normal voltage with a time delay of 5 Sec. The

time delay now have been revised as follows :

(1) ISP-Nagda-4Sec. (2) ISP-Sarni- 5 Sec. (3) ISP- Indore-I – 5sec (4) ISP- Indore-II – 6sec.

Though the SCADA data have indicated voltage in the range of @ 420 to 425 kV, ISP-Sarni

line tripped on over voltage. ISP-Sarni line O/V setting were raised to 114% (5 Sec.), still it

tripped even though the SCADA data was showing 425 kV. He further intimated that on

28.1.2012 ISP-Sarni line tripped on Main-II. However, ISP-Nagda having 4 second delay did

not trip. R-phase voltage at Sarni and ISP end recorded was about 10-12 kV higher than Y &

B Phase voltage.

MPPGCL representative informed that the O/V relays are REL521 for Main-I and REL 670

for Main-II and the relays are configured to sense phase to phase and mainly R-phase is

involved in the tripping.

PGCIL representative stated that Reactors have been provided at Vandana & Balco ends.

WRLDC representative stated that Sarni-ISP being a very long line Bus reactor may be

installed at ISP end. He further informed that with the upcoming generation at Balco (2x300),

it would be difficult to control the O/V in this area, PGCIL representative stated that line

reactors are required to be installed at Birsinghpur end, since the loads are not available on

these corridors. MPPGCL representative informed that there is space constraint at

Birsinghpur for installation of new Reactor.

WRLDC representative agreed for carrying out the study & give the capacity of Reactor

required to be installed at ISP.

Committee members felt that the above tripping looks to be ambigious due to either

improper SCADA reading or O/V relay malfunctioning. Committee felt that for the

time being stand alone relay for over voltage protection may be installed. Committee

requested WRLDC to carry out studies and give the rating of Bus Reactor to be


installed at ISP. Committee requested MPPTCL to verify the status of transposition of

ISP-Sarni line and S/S earthing. Looking at importance of the matter, Committee

decided to review the matter in due course.

2.3(vii) Occurrence at Birsinghpur on 8.11.2012


On 08.11.2012 at around 13.53 Hrs, at SGTPS, bus-bar protection operated at 400KV bus-II.

This has resulted into tripping of 500MW unit No.5 and 400KV Birsinghpur-Damoh I &II,

400KV Birsinghpur-Balco feeder. Bus-bar protection on bus-II mal-operated and kept off for

testing and checking of protection.

MPPGCL representative intimated that PLCC trip check /testing was being carried out at

Katni end. DT was received at Birsinghpur end since Bir,pur –katni line was out. He further

informed that Main-I & II LBB has been enabled since Areva-442 relays have inbuilt LBB.

Committee felt that the inbuilt LBB of main-I & II may not be enabled/used, therefore

a separate LBB relay or LBB along with B/B protection should be installed to avoid

such occurrences. The MPPGCL was requested to implement the above protection

scheme at the earliest.

2.3(viii) Occurrence at Birsinghpur on 10.11.2012


400kV Bus bar Protection was taken out of service for testing due to operation of LBB on

08/11/12 (refer item No. 2.3(vii)). On 10.11.2012 at 05.30 hours the 400 KV BRS-Damoh-I

(PGCIL Feeder) “B” phase, Bus-II Isolator damaged due to heavy flashover and resulted in

Bus fault in 400kV Bus-II. This caused tripping of 500MW Unit-5 , ICT and 210MW Units-

2,3&4. Within One sec. all outgoing feeders connected to 400kV Bus-II tripped on operation

of reverse zone and DEF of DPS along with Bus Coupler tripped on E/F Protection

400/220kV ICT tripped on “Neutral Displacement” Protection. Before isolation of 220kV

Bus through ICT, 210MW Units 2,3 & 4 on 220kV Bus Tripped through “Backup

Impedence” & “GT Stand by E/F”Protections . The 500MW Unit-5 tripped on “Over

voltage” Protection.


Operation of LBB Protection was referred to M/s Alstom T & D India Ltd., the OEM for Bus

Bar Protection, who investigated and suggested adjustment in the settings of LBB Protection

in P442 relay. Matter taken up with PGCIL for checking and replacement of faulty

equipments and through checking and preventive/ predictive maintenance of all equipments

for their feeders. Relay timings of Back-up E/F Protection of ICT and GTs of PH-I & II are

being reviewed.

MPPTCL have informed that on at around 05.30 Hrs, flashover observed in B-phase Bus-II

isolator of 400 KV Birsinghpur-Damoh- I PGCIL feeder at Birsinghpur. Subsequently all

400 KV feeders along with 500 MVA ICT (400/220KV) & 210 MW running units No.2, 3, 4

& 500 MV unit No.5 also tripped. Faulty section was isolated and system was normalized in

due course of time. As the bus bar protection of Birsinghpur was kept out of service , the

flashover in B-Phase Bus II isolator of 400 kV Birsingpur-Damoh -I line led to feeding of the

fault by all the feeders connected in Bus-II. This resulted in tripping of all the feeders on

operation of reverse zone protection & DEF of DPS. The delay in tripping of 400/220 kV

ICT led to sensing of this fault by 220 kV side generators and their tripping. During that

time 400 kV Damoh-B’pur ckt-I was undergoing LILO work at Katni which was completed

by 9th Nov’12 and the line is at present 400 kV Damoh-Katni I and Katni-B’pur I. The

system was restored immediately by keeping out Bus Bar protection for inspection.

The 400 kV B’pur –Damoh -II was hand tripped by station operator by mistake instead of

faulty line 400 kV B’pur-Damoh I. On analysing the event, it was found that the protection

scheme being used at 400kV Birsinghpur is of non-numerical in nature. The delayed tripping

of 400/220 kV ICT which led to feeding of fault to 220 kV side eventually resulted in

tripping of units is also an issue which need to be investigated. Also operating the system

without any bus-bar protection was very undesirable and made the whole system vulnerable.

Such practices may be avoided.

Further, ED(Engg), MPPGCL vide letter dated 3.12.2012 have raised concern due to failure

of equipment on PGCIL feeder at early spans which are offering threat to operation of

thermal units by which MPPGCL will suffer heavy financial losses and create major system

disturbance.

Committee felt that insulator flashover and other equipment failure in the area may be

due to overvoltages in the area. Committee recommended that the Bus bar protection


should not be kept out of service for prolonged duration and problems associated with

B/B protectection should be taken up on priority.

2.4: System disturbances in MSETCL/MSPGCL system.

2.4(i) Occurrence at 400 KV Girwali S/S on 9.07.2012

MSETCL representative explained the occurrence as below :

On 9th July 2012 at 16:02hrs, 400 kV Bus bar protection of Main Bus-2 at 400KV Girwali

Substation operated. It was heavily raining at the instant of fault. The tripping was due to

striking of arc between corona ring of A phase of Main bus 2 and C phase of stub bus of

PGCIL ckt 2 bay. The reason for arc stroke was low clearance between Main bus and Stub

bus in PGCIL bays due to non adherence to the standard clearences in construction. Bus

arrangement, corona ring, diagrams showing various clearances etc. is enclosed at

Annexure-2.4(i).

Restoration activity for tripped lines & Equipments started except 400 kV PGCIL-II bay

which was suspected for the bus occurrence. The busbar protection has operated for a bus

zone 2 fault as operating current for A phase exceeded 80% of restraining for that phase. The

busbar protection disturbance record shows presence of AC fault throughout the fault

duration. All the line and ICT at Girwali end fault records also show presence of AC fault in

reverse direction (i.e. towards bus) except the PowerGrid circuit 2. The PowerGrid circuit 2

has extended Zone 1 tripping at both ends. The PowerGrid circuit 2 & busbar protection

records indicate presence of a fault involving bus and line (A phase of bus and C phase of

line). The fault current recorded is @ 12000A. From the PowerGrid circuit I & 2 records

some problems with respect to instrument transformer secondary grounding were also

suspected.

MSETCL have further intimated that on switchyard inspection; it is observed that in

PowerGrid ckt 2 bay; the clearance between A phase of main bus 2 and C phase of stub bus

(line in effect) is less compared to other phases. A fault at this location can produce current

distribution as seen in the disturbance records. The PowerGrid Engineers informed that the

tripping of both PowerGrid circuits at their end in Zone 1 was due to Zone 1 reach being set

to 120% wrongly. The same is now corrected by them. It was observed that the instrument

transformer grounding in Powergrid bays was carried on relay panel side. Further tracing


revealed that these panel side earthing strips get connected to cable trays in the cable gallery

and not to the earth mesh directly. The connection point at cable trays shows some black

markings. . This kind of earthing can create problems in relay measurement. In PGCIL Ckt I

& II the distance protections are connected to the CT cores with Knee Point voltage 1000V

and Bus bar protec;ion is connected to 4000V. This is not matching with the approved

drawings.

PGCIL representative intimated that the contract was awarded on trunkey basis, and the

works were carried out by M/s Siemens Ltd. The clearances have now been provided in

accordance with the standard specifications.

Committee expressed that clearences in S/S yard be maintained as per standard

specified in IS and strict supervision as regards to clearences to be maintained, so as to

avoid such occurance. Also standard earthing practices in respect of Instrument

transformer be followed and appropriate CT cores be wired up in DPS & B/B protn.

scheme.

2.4(ii) Occurrence at 220 KV S/S Mudshingi on 10.07.2012


On 10.07.12 at 22:20 hrs, 220 KV Talandge- Mudshingi- I line tripped on distance protection.

’R’ Phase Pilot insulator string flashover took place at location number 8 (12.51 KM from

Mudshingi) on 220 KV Mudshingi-Talandge ckt.- 1. 220 KV Mudshingi- Talandge - 1 CB

tripped from Mudshingi end in Zone - 1. From Talandge end the fault was sensed by the

relay in Zone - 2 correctly and the trip was initiated by both Distance and Earth fault relays.

Circuit Breaker ’Y’ and ‘B’ pole opened but due to mechanical problem, ‘R’ ph. Pole

failed to open at Talandge. This is not sensed by LBB protection, since LBB element of

this feeder found faulty. Due to mechanical problem in CB of 220 KV Talandge- Mudshingi

Ckt- I, delayed operation of PDR & also problem in LBB, the remote end tripping of source

feeders occurred.

MSETCL have further intimated that after analysis PDR time lag found 500ms (AREVA

Make) and ‘R’ phase LBB element of 220 KV Talandge – Mudshingi Ckt- I was found

faulty.


MSETCL representative further informed that the PDR setting adopted is 400ms, which is

more than Z-2 timings of DPS. MSETCL representative informed that the PDR setting have

been revised to 150ms. s & the faulty LBB element was replaced.

Committee observed that tripping from remote ends in Z-2 was due to non-clearence of

fault by R-ph pole, since the pole failed to open due to mechanical problem (stuck

breaker condition) therefore regular maintenance of CBs should be carrird out.

2.4(iii) Occurrence at 220 KV S/S Wardha on 15/16.08.2012


On 15.08.2012, 220 KV Wardha-Khaparkheda line (107 KM) tripped at @ 23:18 Hrs on

distance protection from both ends. The Ckt auto-reclosed at Khaparkheda end successfully.

At 220 KV Wardha S/S, B-ph trip command issued by the distance relay (Make: Siemens

Type:7SA611)of 220 KV Khaparkheda feeder and fault was isolated; A/R close command

was issued to breaker but since B-pole closing coil was burnt, breaker did not close and

finally tripped on PDR. A/R close command output contact of relay binary output damaged.

At 23:40 Hrs, trial taken by AE, shift incharge to charge the line through main breaker in

local mode from yard but breaker did not close and again tripped on pole discrepancy. Line

was in charged condition from Khaparkheda end and charging current was about 40A which

was normal. Hence it was decided to charge ckt through TBC. At 00:45 Hrs on 16.08.2012,

after carrying out necessary operation to shift 220 KV Khaparkheda ckt on TBC, TBC

breaker closed. But immediately tripped with distance protection on B-ph, Z-1,General trip

indication with distance 7.6 KM, IL3=10.51 KA, B-ph O/C relay, 86B, the operation of

internal LBB feature of 220 KV Busbar protection (Make: NR electric, Type: RCS915). Due

to operation of LBB protection of 220 KV Khaparkheda feeder at Wardha S/S, all feeders

connected to 220 KV bus including 220 KV Khaparkheda ckt tripped and 220 KV bus

became dead. Load @ 270 MW was affected due to above trippings. At about 01:05 Hrs on

dt.16.08.2012, 220 KV bus at 220 KV Wardha S/S charged from 220 KV Warora S/S and

stood Ok. Normalcy of rest of the feeders and T/Fs except 220 KV Khaparkheda ckt

restored one by one latest by 01:43 Hrs. At about 06:04 Hrs, after replacement of closing coil

of main breaker of 220 KV Khaparkheda Ckt and after taking trip-close trials of breaker,

second trial of breaker with auto reclose OUT was taken but again tripped on distance

protection on B-ph, Zone-1, General trip indication with distance=7.4 KM, IL3=10.32 KA


and 3-ph trip relay 186. Breakdown was declared on line.

In line patrolling at location no.315 cut point, insulator string found burst and conductor

found snapped. After attending line breakdown, the line charged on dt.16.08.2012 at 19:58

Hrs and stood OK.

MSETCL further intimated that at 220 KV Wardha S/S, Single bus system (1 M+1 A bus

arrangement) is provided for 220 KV bus. On patrolling of line on dt.16.08.2012 at location

no. 315 at cut point, B-ph string insulator found burst and conductor found snapped which

created fault. Hence tripping of line on distance protection at both end is in order. Due to

opening of conductor, fault was created towards wardha end. The line auto-reclosed at 220

KV Khaparkheda S/S successfully. At Wardha S/S due to burning of closing coil of B-ph

pole of 220 KV Khaparkheda feeder breaker, the line did not reclosed though the A/R

command was initiated by distance relay and line tripped on PDR. At about 00:44 Hrs, the

line charged through TBC due to problem in main breaker. Due to persistent fault, distance

protection and back up protection were operated but TBC breaker did not trip. Hence LBB

protection of 220 KV Khaparkheda feeder operated (Internal feature of Busbar scheme).

From the distance relay event log, it was observed that auto reclose was not disabled. Auto

reclose gets disabled when N/T switch is shifted to ‘T’ position. This indicates that N/T

switch was not shifted to ’T’ position before closing of the TBC breaker. As the N/T switch

was not shifted to ‘T’ position, protection of Khaparkheda ckt was not transferred on TBC

breaker, Hence trip command due to operation of distance protection and back up O/C relay

was not extended to TBC breaker. Due to external LBB initiation through distance and back

up protection to bus bar protection relay, re-trip command issued after 100 msec to

Khaparkheda breaker from bus bar relay which was not extended to TBC breaker. Hence

fault current was persisting. Thus internal LBB function of bus bar relay operated after 200

msec which issued final trip command to all breakers including TBC. About 10.77KA current

in B_ph was recorded by busbar protection relay (Type:RCS915). Thus the operation of LBB

protection is IN ORDER though undesired.

MSETCL have suggested following remedial actions :

1. It is essential to wire up the closing interlock of N/T switch contact in remote closing of TBC breaker where-ever it is not available. In the present case, it is not available in the scheme. Instructions have been issued to make necessary modification in the scheme.


2. Aux relay should be used in A/R reclose ckt where it is not available. Reclosing command is to be routed through contact of aux. relay.

Committee observed that during the tripping of Khaperkheda-Wardha line the

conductor snapped & the snapped conductor of Khaperkheda-Wardha line might have

remained in contact with earth from Wardha end and the snapped end of conductor

from Khaperkheda end remained isolated from the fault.

Therfore A/R was successful from Khaperkheda end & the line section remained in

charged condition from Khaperkheda end. During A/R from Wardha end due to

closing coil problem the breaker did not close. The snapped conductor from Wardha

end remained in contact with earth.

After transferring the line on TBC at Wardha end (without putting the switch in ‘T

‘Position) due to persisting fault the trip command was not extended to the TBC and

the fault was cleared , resulting in the operation of LBB protn. Committee expressed

that due care should be taken while transfer of main CB of line to TBC and suggestion

at Sl.no 1 & 2 be complied.

2.4(iv) Occurrence at 220 kV Khaparkheda on 22.08.2012


At 09:40 Hrs on 22.08.12, due to Y phase CT blast of 40 MVA station transformer-III there

was smoke and fumes leading to conductive medium formation. This led to bus fault on

220kV Main Bus-I and initiate the tripping of all elements connected on Bus-I. This resulted

in tripping of Khaparkheda Unit 1 and 3. However the tripping of 220 KV GT-2 which was

on Main bus-2 is undesirable. After enquiry made at PCR end, it is revealed that the GT-2

has tripped during the occurrence due to flame failure and not due to operation of any

electrical protection.

Simultaneous to this the occurrence, 400/220/33KV 500 MVA ICT-2 at 400KV

Khaperkheda S/S tripped on differential protection Y & B phases. The tripping of ICT may

be due to flowing of zero-sequence current through the 220KV CTs of ICT. The

400/220/33KV 500 MVA ICT was on no-load due to failure of 220KV CT since 29/06/2012,

by removing the jumpers of 220KV side & jumpers were tied to the gantry structure. Also

the earth switch of 220KV side of ICT was kept closed resulting in dual side earthing of CT.

Dual side earthing of CT provided the path for flow of zero sequence current through 220KV

side CT resulting in tripping of ICT on diff. protection.


Details submitted by MSETCL are enclosed at Annexure-2.4(iv). Committee recommended for carrying out the diagnostic test of equipments regularly

and follow maintenance schedule strictly, since the Bus fault at generating station is

very severe to the system and may lead to cascade trippings so the practice should be

there.

2.4(v) Occurrence at 400 kV Wardha S/s on 8.10.2012

SLDC, MSETCL reported that 400 kV Wardha-Mouda-1, Akola-1 and Warora-1 lines

tripped on overvoltage while charging 765 kV Wardha-Seoni-II at 9:54 hrs on 8.10.2012.

Also, 765 kV Wardha-Seoni-II tripped simultaneously. As AMPL at Tiroda was evacuating

power on 400 kV Tiroda-Warora-Wardha on single circuit, due to tripping Wardha-Warora

line, AMPL Unit-1 lost due to no evacuation affecting 375 MW short term open power

schedule to MSEDCL. SLDC control room was not intimated prior about any charging.

Committee observed that due considerations should be given to the real time system

conditions and proper assessment of the real time system condition should be done

before putting the transmission element into service.

2.4(vi) Occurrence at 400 kV Padghe on 25.08.2012

MSETCL representative explained the occurence as below :

On 25.08.2012 at 05.57 hrs, the LBB Protection in respect of 400kV HVDC-1 operated,

resulted into tripping of all feeders & ICT`s connected to 400kV Main Bus-1 at 400kV

Padghe s/s. The 400 kV HVDC-1 bay was connected to 400kV Main bus-1. On 25.08.2012

at 05:26:23:721hrs, HVDC Bipole power made zero as per instruction from SLDC, Kalwa.

Subsequently, AC filter (Z1:H12, Z2:HP24/36) CB open command initiated through RFC

(Reactive Power Control) automatically. The unbalance protection level 1: R, B operated

indicating trip of R & B pole of filter CB. Further ground fault protection AFP100 for filter

Z1 & Z2 operated and initiated trip command to filter CB. The operation of both unbalance

protection level and ground fault protection indicating non opening of Y pole of filter CB i.e.

Y pole of filter CB was found to be open partially. Due to partially opening of Y Pole of

filter CB, the breaker failure protection BOP100 for filter CB operated (set 180mA/100msec)

initiating trip command to convertor CB, filter CB in HVDC yard and 400KV HVDC - I CB

at 400KV Switchyard. However, all three poles of convertor CB (ACCB) were found to be


open.

The breaker failure protection BOP100 of filter CB initiated trip command to 400KV CB at

400KV Padghe switchyard. At this instant, the SF6 gas lockout & trip circuit – 1 & 2 faulty

appeared resulted into CB lockout condition. Subsequently, the PDR (set time delay

100msec) operated and tripping R & B pole of 400KV HVDC – I CB and Y pole remained

closed due to CB lockout condition. The LBB protection of HVDC – I CB did not operate at

this instant as the current was not sufficient to operate the relay (LBB relay set to O/C = 0.8A

with time delay 200msec). The over current / ground protection RACID relay (set OC:

500mA/500msec, HS:2000mA/100msec) was found to be operated and reset frequently due

to internal arcing took place inside Y pole of filter CB.

Finally at 05:57:32:295, the Y-pole of filter CB burst in HVDC switchyard, resulted into

operation of AC bus differential protection TRP100. (set I diff = 500mA/40msec) which has

again initiated trip command to convertor CB (ACCB), filter CB in HV DC yard and 400KV

HVDC – I CB in 400KV Switchyard. Due to lockout condition of 400KV HVDC – I CB, the

LBB protection of HVDC – I CB operated at 400KV Padghe s/s. This has resulted into

tripping of all 400KV lines and ICTs connected to 400KV Main bus – I at Padghe s/s. The

fault current recorded was 38.7kA (as per DR).

The 400KV HVDC – I CB BHEL make (Sr. No. 401920B Type: 3AT4, YOM: 1996, DOC:

1999) last tested on 17.02.2011. During the testing ‘contact resistance measurement & time

test are carried out and test result were found to be in order.

Subsequent to the occurrence, the CB time measurement was carried out and trip time of TC

– I / TC- II measured to be 341.6 msec & 342.0 msec respectively. TC – I / II resistance value

measured to be 20.6 kΩ instead of 75Ω. Both Y ph trip coil & resistance were replaced with

spare coil & resistance. The timing measurement was carried out till the Y pole trip coil I / II

time measured to be 159.0 msec & 158.6 msec respectively. Finally the trip coil I / II

mechanism dismantle and it was observed that trip coil electromagnetic plunger found

sluggish. The trip coil assembly was replaced by spare one. The time measurement was

carried out and was found to be in order. The operation of LBB relay in respect of HVDC

CB is due to non operation of Y pole of CB due to its lockout condition.


The AC filter CB ABB make (Sr.No.8261669, Type HPL 550/31B2, YOM: 1996, DOC:

1999) last tested in Aug-2009. The overhauling of said CB is carried out by M/s ABB. The

CRM & time measurement was carried out after overhauling of mechanism and test results

were found to be in order. The said CB has successfully cleared the fault on 16.08.2012 due

to operation of unbalance level - 3 alarm of filter Z1 – Z2: R phase.

Further lot of blocking / de-blocking operations of HVDC Bipole link is carried out as per

instruction of SLDC, Kalwa to control the system over voltage. The total no. of block / de-

block incidents during this year was about 128 Nos, resulted into deterioration of service life

of CB due to its frequent operations. The partial opening of Y pole CB and subsequent

failure may be due to frequent operation of CB during blocking / de-blocking operation of

HVDC Pole.

Committee felt that above trippings due to stuck breaker condition were in order,

however overhauling and timing tests of the CBs should be carried out regularly for

early detection of deteriorating conditions of the CB. Also, frequent block/deblock

operations of the HVDC Bipole link should be minimized to avoid stress on the filter

circuit breakers at HVDC.

2.4(vii) Occurrence at 220 kV Uran S/s on 30.10.2012

MSEGCL representative have explained the occurrence as below :

On 30/10/2012 at 05:58 Hrs , GT 8 LBB protection operated due to B phase pole bursting

of 220KV CGL make Circuit Breaker tripping all feeders/equipments connected to the

220KV Main Bus-I. B phase pole of 220KV CGL make SF6 breaker of GT U-8

burst/shattered. The insulator of B pole power contact found completely shattered. The male

contact towards Bus side found rested on bottom post insulator. Top female contact with

conductor connected to GT TF side isolator found snapped. However this has not created any

earth fault from generator side & Bus side as well. It has developed Unbalance current in GT

U-8, resulting in operation of Unbalance protection. At this time, the healthy R & Y pole

failed to trip due to Lockout condition created by above incidence. The failure of breaker to

trip initiated LBB protection which resulted into tripping of all the feeders & equipments

connected on Bus-1 along with B/C breaker. The Main Bus –II remained healthy.

The faulty breaker pole was replaced by spare pole and kept ready with all pre-


commissioning tests completed to shift GT Unit – 8 on own breaker on 31/10/2012.

The Breaker pole seems to have failed due to internal arcing between male & female contact

due to improper contact developed during in-service period. Heavy arcing pits are observed

on male & female contact. Further analysis is being done & matter has been referred to

manufacturer by OEM. The comments are awaited.

Committee felt that the as decided in the previous PCM meetings, specifications for

CTs/CVTs/CBs should be made stringent with performance warranty clause so that the

equipments blasting/failure are reduced. MSETCL/MSEGCL were requested to

provide the observations of manufacturer/OEM.

2.4(viii) Occurrence at 220 kV Uran S/s on 6.12.2012

MSEGCL representative have explained the occurrence as below :

On 06/12/2012 at 01:25 Hrs , WHRP BO Unit B phase Potential transformer burst resulting

in to operation of Bus bar protection in respect of Main Bus II at 220 KV GTPS Uran

Substation tripping all feeders/equipments connected to the 220KV Main Bus II. 220 kV

B phase synchronizing PT of Telk make in the Bay of B0 Unit failed which resulted into

Bus fault on Bus II.The PT lies in Bus Bar Zone & unit connected to Bus II. The Bus Bar

protection of Zone II operated correctly & tripped all the feeders & equipments connected to

Bus II. The New Bus Bar ABB REB 670 which was kept on alarm mode was also found to

be selectively operated. The PT failure was due to primary insulation failure being age old

equipments.

Committee felt that regular maintenance of the instrument transformers be done.

Further the BB protection should not have initiated the trip command, since the same

was put in ‘Alarm’ mode. The matter may be taken up with the manufacturer.

2.4(ix) Occurrence at Nashik TPS

Nashik TPS-3 on 21.11.12

MSPGCL have intimated that Unit 3 was synchronized to grid at 05:00 hrs on 21.11.2012

after normal operations. After synchronizing the unit to grid and picking up the load to

80MW; unequal currents in three phases of generator were observed and at 5.20 hrs negative

phase sequence alarm occurred. The Negative phase sequence alarm is occurred due to the


problem persisting in 220 kV generator breaker. GCR on duty I/C was asked to shift the load

on transfer bus with permission of SLDC.

Meanwhile, Unit-3 tripped at 06:05 hrs on busbar protection due to flashover in

220KVgenerator breaker B-pole. Even though the tripping was initiated on bus bar protection

from GCR & from PCR-3 on 86 GT, the breaker poles were found in closed condition.

Breaker suspected mechanically jam in closed condition. Due to operation of busbar

protection, Stn. X'mer-S was also tripped.

Nashik TPS-3 on 8.12.12

At 01:45hrs on 8.12.12 Unit-3, Unit-4, Station Transformer No.3&4(C3, C4) tripped on

busbar protection due to bursting of Bus Section-II B-phase CT in 220kVswitch yard towards

Unit-5 side. The bus bar protection simultaneously operated, resulting in isolation of bus bar

zone-I and II. In zone-l, Unit No3 T.A set and station transformer no 3 tripped. In zone-II,

Unit No 4 T.A set and station transformer no4 tripped. Unit No 5 did not trip being in bus bar

zone-III, but due to tripping of station transformer 3 and 4, all auxiliaries charged from them

were tripped(e.g. CTLP, CT fans, SSB etc). This has resulted in Local AC failure.

Unit 5 related - Due to tripping of station transformer no 3 & 4, the CTLP's running CT fans,

all other auxiliaries on station bus were also tripped. Load reduced to minimum upto

125MW. 220kVswitchyard isolator polygon (Generator unit 4 side) in bus bar zone-I was

found also damaged. Due to isolation of bus zone-I & II, all the lines in bus zone-I & II i.e.

ICTs(1, 2, 6), 220kVAiroli /BBLR line-l / Ghatghar line/ Unit no.3 &4/ station transformer

3&4 tripped.

Station transformers No.3&4 were charged from 220 KV HV side at 02:43hrs and 03:05 hrs

respectively. The faulty B-phase CT in bus section-II (Sr. No.2010-58, M/s SCT make, Ratio

2400-1200/1A) was replaced with another CT(Sr.l o.2010-69, make M/s SCT, ratio 2400-

1200/1A, cap - 444.98bf, Tan delta - 0.209 %). The faulty CT was installed recently on

18/10/2012 & failed in 41 days. Also C and Tan delta of other CTs are measured and four

nos. of them are having higher tan delta values and their trend is rising. Bus section-II CB is

kept off. The unit is synchronized to grid through transfer (auxiliary) bus. LPT(front left)

diaphragm was replaced by TM.

The faulty CT was installed on 31/10/2012 and failed in 41 days. It was replaced with another

one. The busbar zone I &II were isolated on bus bar protection resulting into tripping of unit


no 3 & 4 T.A. sets, station transformer no 3&4.

As MSEGCL representative was not present for the meeting the matter would be

discussed in next PCM.

2.5 Occurrences at Goa

North Goa : 8.10.2012

At 04:04 Hrs, 400 kV Kolhapur-Karad I, Kolhapur-Mapusa-I, Karad –New Koyna-I and

Karad –Jaigad- I line tripped on over voltage. This led to loss of feed to Goa from WR Grid

as the other 400 kV and 220 kV Lines from Kolhapur were already out to control H/V. The

complete Goa load except Vasco tripped and led to 250 MW load loss.

400 kV Kolhapur-Mapusa -II and Karad-Kolhapur- II were already out on high Voltage. 220

kV Mapusa-Ponda I LILOed at Amona and Kolhapur-Ponda and Tillari-Ponda are LILOed at

Amona. These circuits are named as Amona-Ponda-I (Mapusa Line), Amona-Ponda-II

(Kolhapur Line) and Amona-Ponda-III (Tillari Line). Amona-Ponda-II and Amona-Pond III

were opened fromPonda end at Gantry at 23:40 Hrs on 7th Oct, 12 by Ponda to control High

Voltages on lower kV levels. At 04:04 Hrs, 400 kV Kolhapur-Karad I, Kolhapur-Mapusa-I,

Karad –New Koyna-I and Karad -Jaigad I lines tripped on High Voltage. This led to loss of

feed to Goa from WR Grid leading to load loss of 250 MW. Vasco Load (15 MW) got

transferred to REL in island mode. Restoration:Initially after the occurrence the alternate

power of 110 MW was availed from SR grid to meet the VIP/Domestic loads. Vasco load got

transferred to REL in island mode. The Old MSEB Circuits from Amona were restored at

06:25 Hrsand 400 kV Kolhapur-Mapusa D/ C at 06:35 Hrs. System was successfully

normalized by 07:00 hrs.

Goa : 24.10.2012

At 17:10 Hrs, due to failure of jumper 220 kV Kolhapur-Ponda I tripped which led to total

loss of supply to Goa. Prior to the event others lines werenot available to Goa due to tripping

of 400 kV Kolhapur-Mapusa II on over voltage and 220 kV Tillari-Amona and 220 kV

Mahalaxmi-Amona on DPR operation. This led to complete loss of Goa load i.e. 244 MW.

At 16:33 Hrs, 400 kV Karad-Kolhapur I Tripped on Over-voltage ( Ckt II was already out to


control H/V). At 17:05 Hrs: 400 kV Kolhapur-Mapusa II tripped on Over-voltage ( Ckt I was

already out to due H/V). Now Goa was connected with WR region from220 kV Kolhapur-

Ponda I (Ckt II was out for retrofitting work ). At 17:09 Hrs: 220 kV Tillari-Amona and

Mahalaxmi-Amona tripped due to DPR operation. Now the Goa supply was fed through 220

kV Kolhapur-Ponda I whose jumper melt due to overloading at 17:10 Hrs due to high

loading leading to complete loss of supply to Goa.

Restoration:Initially the Power from SR was taken to supply power to VIP and Domestic

load. The restoration started with taking 220 kV Tillari-Amona at 17:38 Hrs and 220 kV

Kolhapur-Ponda II at 17:45 Hrs. Then After 220 kV Mahalaxmi-Ponda was taken back at

17:48 hrs. 400 kV Kolhapur-Mapusa II line was taken in service at 17:56 Hrs.

It was seen that after the tripping of 400 kV Kolhapur-Mapusa II, the loads at Tivim were

also fed from Ponda from only one available 220 kV Amona-Ponda line of Kolhapur side. As

total load of 250 MW fed from this line (made of Locust conductor) jumper at Ponda Gantry

got melted due to over-current/overload and resulted in loss of supply to Goa. However as

intimated by WRLDC via. Msg.No: WRLDC/MO-II/2012/7372 if the bus coupler at Amona

would have been in closed this situation could have been averted.

Goa : 13.11.2012

At 16:35 Hrs, due to tripping of 400 kV Kolhapur-Mapusa II Goa lost its supply from

Western region leading to a load loss of 200 MW. Earlier tothis event and 220 kV Amona-

Ponda I & II tripped on over voltage at 16:05 Hrs. At 16:05 Hrs: 220 kV Amona-Ponda I &

II tripped on over voltage and the same was not informed to RLDC. Also the Amona Bus

coupler was not closed. At 16:35 Hrs: The only available circuit to Goa i.e. 400 kV

Kolhapur-Mapusa II tripped on over voltage. This led to loss of supply to Goa from Western

region leading to complete loss of load of Goa which was being catered through WR system.

3 repeated attempts of restoration of 400 kV linesand 220 kV Lines got failed due to

continued Overvoltage in view of dropping demandon Diwali. Initially the power to domestic

load/VIP load were catered through SR grid from 17:10 Hrs. 220kv Amona-Ponda I & II got

restored at 18:10 hrs and 400kv Kolhapur - Mapusa Iat 18.15 hrs thus normalizing the full

WR network of the Goa by 18.20 hrs.

It was found that the 220 kV Amona-Ponda I & II tripped at 16:05 hrs but the same was not


intimated to SLDC. Also the bus coupler of Amona which should have been closed as per

Msg.No.WRLDC/MO-II/2012/7372 but same was not followed. If the Amona Bus Coupler

would have been closed after tripping of 220 kV lines the situation could have been averted.

Commitee felt that the disturbance in Goa due to persisting high voltage problem has to

be resolved as earliest as possible.This being the third incident in the Goa leading to loss

of supply to Goa from Western region due to persisting high voltage problem at Karad,

Kolhapur, Sholapur and Mapusa in the recent months. There is a need to provide

adequate VAr support at the above substations along with Ponda S/s.

MSETCL representative informed that the over voltage setting of 400kV Mapusa-

Kolhapur at Kolhapur end have been revised from 110% to 112%, as decided in OCC.

ITEM NO. 3: Tripping of lines / ICTs:

The incidences of tripping of lines and ICTs during the period 01-07-2012 to 30-11-2012 are

enclosed at Annexure–3.

Committee may like to note/discuss.

ITEM NO. 4: Status of implementation in WR on Recommendations of Report on Grid disturbance on 30th and 31st July 2012

The updated status of implementation in WR on Recommendations of Report on Grid

disturbance on 30th and 31st July 2012 is given at Annexure-4.

ITEM NO. 5: Implementation of Automatic Demand Management Scheme.

Member Secretary I/c WRPC stated that Hon’ble CERC vide order dated 14.01.2013 on

WRLDC petition No. 249/MP/2012 have directed RPCs to discuss the issue of

“Implementation of the Automatic Demand Management Scheme at the SLDC/Distribution

Company level”.

In para 9 of aforesaid order CREC have quoted that

Quote

We have considered the submissions of the parties. With regard to the submission of NLDC

that overdrawal irrespective of the frequency should not be allowed, we intend to clarify that


at present, UI Regulations and Grid Code allow overdrawal within prescribed limits in

normal situations and therefore, no such directions can be issued which would be contrary to

the regulations. The petitioners have also sought directions from the Commission to the

States to implement Automatic Load Management Scheme and to provide the details of the

feeders which can be included in the Automatic Demand Management Scheme. We had

directed NRLDC in our order dated 17.8.2012 in Petition No.125/2012 to identify in

consultation with the CTU, CEA, STUs and SLDCs the feeders of the State network which

are incidental to the inter-State transmission of electricity which can be opened in case of

sustained overdrawal from the grid or any other imminent danger to the grid. In the context of

our direction, we are of the view that RLDCs need to be properly equipped to disconnect the

pre identified feeders in the State networks in the event of overdrawal which poses imminent

danger to the grid. To achieve this objective of automatic demand management scheme, there

may be technical and system constraints which need to be addressed through appropriate

technology. Since such technological improvements involve capital cost, we are of the view

that such proposals should be discussed at the RPC forums as an agenda item and the

recommendations/decisions of the RPCs should be placed before the Commission for

consideration and necessary directions.

Unquote

WRPC Secretariat vide letter dated 16.01.2013 addressed to Secretary, CERC have intimated

that the issue will be taken up for discussion in the Protection forum of WRPC on 30th and

31st January 2013 followed by discussion in OCC forum on 11th and 12th February where

Distribution companies also involved. Thereafter the decisions will be placed before the RPC

meeting as an Agenda item which is scheduled to be held on 25th and 26th February 2012.

The discussion/direction of the RPC shall be communicated to various constituents of

Western Region for implementation.

GM, WRLDC made presentation on GSES during the meeting. The 10 logical conditions

envisaged and control actions proposed by WRLDC were as follows:


Sl. No Logic Control Action Manual or Automatic

Measurements as input for control action

(Local / Wide Area)

Control Action (Local / Wide Area)

1 ∆ P > 150 MW

∆ P = Actual-Schd

and freq< 50 Hz

Shed load in Constituent. In identified groups. Each group constituting 150 MW or 12% of the Schedule.

Rotation logic and sequence to be programmed at SLDC and WRLDC PLC

Stage 1 : Manual

Stage 2 : Automatic (From SLDC PLC after 15 minutes)

Stage 3 : Backup (from WRLDC PLC after 20 minutes)

Wide Area : Schedules & Drawal from SCADA system at LDCs

Wide Area:

signal sent from LDC to selected 220/132/66 kV sub-stations for tripping of feeders to get desired load relief

2 ∆ P < -150 MW

∆ P = Actual-Schd

and freq> 50 Hz

Send signal to designated power stations. Rotation logic and sequence to be programmed at SLDC and WRLDC PLC

Stage 1 : Manual

Stage 2 : Automatic (From SLDC PLC 15 minutes)

Stage 3 : Backup (from WRLDC PLC in 25 minutes)

Wide Area : Schedules & Drawal from SCADA system at LDCs

Wide Area:

signal sent from LDCs /WRLDC to power stations

3 Voltage <200 kV at sub-station for more than 5 minutes

Shed load at selected 220 kV sub-stations identified in S no 1 above.

Stage 1: Alarm (208 kV)

Stage 2: Automatic (200 kV for more than 5 minutes)

Stage 3: 185 kV 30 seconds

Local area:

Bus voltage Measurement at the selected 220 kV substations

Local area:

4 Key line/ICT loading crossing limits

Min(Z3, SIL, stability limit)

Shed load down stream Stage-1: Manual (SLDC level)

Stage-2; Automatic through PLC

Local area: ICTs /Line Loading from SCADA system at LDCs

Wide Area : Signal sent to Substations selected for the ICTs and Line loading relief


5 Flows crossing TTC and ∆ P > 100 MW

Shed load in the feeders identified at Sl. No 1 on rotational basis.

Automatic Local area:

No. of measurements aggregated at LDC SCADA.

Wide Area:

Signal sent from LDC Many areas in state.

6 Sudden loss of generation > 1000 MW or loss of high capacity corridor

Loss of high capacity corridors

Automatic Local area: measurement at Substation on Change of 1000 MW on sum of line flows

Wide Area:

Trip feeders.

7 Angular difference exceeding cut off value

Shed load in designated areas

Automatic Wide Area Synchrophasor measurements at RLDC/SLDC

Wide Area:

Signal sent to 220/132/11 kv substations

8 UFR I: 49.0 Hz

UFR 2: 48.8 Hz

UFR3: 48.6 Hz

UFR4: 48.4 Hz

State peak load: UFR to cover at least 60% of the state peak load . Identify 220 kV substations.

Automatic Local Area Local area:

9 df/dt: 49.9 Hz plus 0.1, 0.2 Hz/sec

Designated feeder in each control area

Automatic Local area Local area

10 Islanding at 47.9 Hz

Power stations, loads Automatic Local area Local area

Details of Automatic Demand Management Scheme to be implemented by GETCO in

Gujarat was presented by GETCO is enclosed at Annexure-5.


Member Secretary stated that Automatic Demand Management Scheme is mandatory as per

IEGC 5.4 clause and as name suggest automatic tripping of feeders are for the purpose of

balancing load and generation and at predefined frequencies. Although ADMS is projected

by NLDC in their scheme as apart of of GSES. It is not a grid security measure as per the ten

grid security scenerio presented by GM WRLDC. The implementation of GSES in toto

requires technology, logic, funding and well defined role of implementing agencies , control

agencies and coordination between discom and transmission group. He requested for

openions from members . Discussion followed ……

Committee members expressed that

(i) DISCOMs should be involved for taking decision especially regarding

identification of loads for tripping under ADSM and GSES, since

prioritization of load to be shed in DISCOMs is not unique and requires

adherence to the regulatory directions.

(ii) As regards to deciding the logic for conditions at Sr. No. 3,4,6 & 7

comprehensive studies should be carried out and the same shall be vetted by

WRPC and constituents of WR. The design of logic and control actions shall

be done in consultation with the DISCOMs, STUs, SLDCs and Generators of

WR.

(iii) As regrds to the AULFS at Sr.No. 8 & 9 requires co ordinate studies among

the WR, NR, ER & NER, since the quantum of load shedding is sensitive to

power number of the NEW grid. The sharing of this load shedding shall be

decided based on the present and future generation and demand senarieos of

the regions.

(iv) Present islanding schemes/ SPS should be taken care off while designing

ADSM and GSES scheme.

It was decided to putup the suggestions in the ensuring WRPC Meeting.

ITEM NO. 6: Date and Venue of the next meeting.

CGPL representative was requested to host the nex protection Committee meeting to be held

during the month of April/May-2013. The date and venue will be intimated separately.

ANNEX-I

1 Shri S.A.Patel Ex. Engineer (Testing),GETCO

2 Shri B.B. Mehta Chief Engineer ,SLDC, GETCO

3 Shri. P S Kulkarni SE (MAHAGENCO), Nagpur4 Shri D.M. Bhadikar EE( MAHAGENCO), Nagpur

5 Shri Sanjay Shinde CE, SLDC, Kalwa.6 Shri Shashank Jewalikar SE (T &C), Auragabad.7 Shri A M Kondawar SE (TCC), Nagpur.8 Shri R.H. Satpute SE(TCC), Vashi.9 Shri J.M.Bansod EE ,SLDC, Kalwa.

10 Shri M.S. Tatte EE(Testing Divn.), Nagpur.11 Shri A.K. Dhapare EE (Testing Divn.), Karad.12 Shri C.L. Bharamgunde Dy.EE (TCC Circle), Karad.

13 Shri P.A.R. Bende CE, SLDC, Jabalpur14 Shri R. S. Shrivastava SE, 400kV S/S, Bhopal15 Shri Sunil Yadav EE (T&C) , Indore.

16 Shri Prakash C. Soni SE (Engg.), MPPGCL,Jabalpur17 Shri R. P. Pandey SE, SGTPS, Birsinghpur

18 Shri M. Z. Rehman Superintending Engineer (T&C), Bhilai

19 Shri G.P. Rai EE (Testing-II), HTPS, Korba

20 Shri M.R. Ingle Executive Engineer ,DD, Daman

21 Shri D.V. Kodge SO/E , TAPS-1&2, Tarapur 22 Shri T. K. Dey SO/E , TAPS-3&4, Tarapur

MPPGCL (Madhya Pradesh State Power Generation Co. Ltd.)

CSPTCL (Chattisgarh State Power Transmission Co. Ltd.)

CSPGCL (Chattisgarh State Power Generation Co. Ltd.)

Electricity Department, DD, Daman.

NPCIL (Nuclear Power Corporation of India Limited)

LIST OF PARTICIPANTS

116th Protection Committee Meeting held on 30th & 31st January 2012 at Nagpur(Mah.).

GETCO (Gujarat Energy Transmission Corporation Limited)

MAHAGENCO (Maharashtra State Power Generation Company Limited)

MSETCL (Maharashtra State Electricity Transmission Company Limited)

MPPTCL (Madhya Pradesh Power Transmission Corporation Limited)

23 Shri Jitendra Tewari AGM (EMD) STPS ,Vindhyachal24 Shri D. Roy Chowdhary AGM , NTPC, WR-II, Raipur25 Shri Abhay G. Sahu Sr. Supdt. , NTPC, Kawas.26 Shri R.Amarendar Reddy Sr. Supdt. , NTPC, Korba.

27 Shri S. Pagare Sr. Mgr., (E), NHDC, Indrasagar, 28 Shri Vinod Kumar Singh Manager(E), NHDC, Bhopal29 Shri Lokesh Gupta E (E), NHDC, Omkareshwar30 Shri D. Roy Asst. Mgr., (E), NHDC, Omkareshwar

31 Shri V.K. Khare GM , WRTS-I, Nagpur32 Shri P.R. Wankhede DGM , WRTS-I, Nagpur33 Shri Ravi A. Wadyalkar Manager , WRTS-I, Nagpur34 Shri Vaibhav Bhandarkar Dy.Mgr., WRTS-I, Nagpur35 Shri Anil Darode Dy. Manager , WRTS-I, Nagpur36 Shri Vijay Shrivastava Dy. Manager , WRTS-I, Nagpur37 Shri Anand Dubey Chief Manager , WRTS-II, Vadodara

38 Shri P.N.M. Rao Dy. Supdt., NSPCL, Bhilai

39 Shri Sanjay K. Prasad Manager , Tata Power, Mumbai

40 Shri Alok Uppal Chief Mgr.(EMD), CGPL, Mundra

41 Shri S.K. Parida AGM(O&M), APL, Mundra42 Shri Sanjay Bhatt Sr. Mgr.( Prot. & Metering), APL, Ahmedabad.

43 Shri H.D. Lakhani Manager (Trans.), Ahmedabad.

44 Shri M. R. Waigankar Sr. Manager (T&P), R-Infra, Mumbai45 Shri K.R. Nerkar Addl. V.P. , R-Infra, Dahanu TPS, Dahanu.

46 Shri S.G.Tenpe General Manager, JPL

47 Shri P. Pentayya GM, POSOCO, Mumbai48 Smt. Pushpa Seshadri Chief Manager (OS), POSOCO,Mumbai49 Shri Ankur Gulati Engineer, POSOCO, Mumbai

50 Shri S.D. Taksande Member Secretary I/C51 Shri M.M. Dhakate Superintending Engineer (P)52 Shri D. P. Singh Executive Engineer (Prot.)53 Shri P. D. Lone Executive Engineer (Comml)

Torrent Power Ahmedabad

REL (Reliance Infra Ltd.)

Jindal Power Ltd.

POSOCO WRLDC (Western Regional Load Dispatch Centre)

WRPC (Western Regional Power Committee)

NHDC

PGCIL (Power Grid Corporation of India Limited)

NSPCL

TPC (Tata Power Company)

Coastal Gujrat Power Ltd.,Mundra

Adani Power Ltd, Ahmedabad

NTPC Ltd.

116PCM ANNEXURE-3

1 400kV Khaparkheda 400kV Kh,kheda-Ch,pur and KoradiLines

MSETCL (Y)

01-08-2012 23:10 03-08-2012 17:30 i) Due to bursting of 400kV r-Ph CT of 400kV Ch,pur. ii) The 400kV Koradi-II bay is adjacent to 400kV Ch,pur bay . Effect of flashover and smoke created fault and damage to B-Ph tie CT of Koradi-II bay between Tie CT and 86B Isolator,Hence teed 2 protection for Koradi-Ii operated..

2 400kV Chandrapur 400kV Ch,pur-Parli-3 MSETCL (Y)

02-08-2012 09:42 02-08-2012 11:50 Line tripprd at Parli end and L/O trip for remote faultat Ch,pur end on receipt of DT signal.

3 400kV Khaparkheda 400kV Kh,kheda-Koradi Lines

MSETCL (Y)

06-08-2012 02:42 06-08-2012 11:23 At 400kV k,kheda S/S, 400kV Koradi ckt tripped due to receipt of DT signal from Koradi.

4 400kV Koradi 400kV Koradi-Akola MSETCL (Y)

13-08-2012 17:40 13-08-2012 18:09 Ckt tripped at Koradi end on receipt of DT signal from suspected problem in PLCC panel at 400KV Akola S/S under Amravati Zone. Scheme has been modified.

5 400kV Chandrapur 400kV Ch,pur-PGCILCkt-1

MSETCL (Y)

22-08-2012 11:20 30-08-2012 12:34 O/V stage -1 operated at GCR end.Y-Ph CVT suspected giving higher O/V at GCR end, replaced by availing outage and line recharged at 12:34 Hrs on 30.08.12(Line maintained by PGCIL)


24-08-2012 16:18 24-08-2012 16:25 Ckt tripped at Koradi end on receipt of DT signal from Akola end.suspected problem in PLCC panel at 400KV Akola S/S under Amravati Zone.

7 400kV Koradi 400kV Koradi-Sarani MSETCL (Y)

25-08-2012 23:10 25-08-2012 23:34 Ckt tripped at Koradi end on receipt of DT signal Sarani end.


05-09-2012 00:27 06-09-2012 07:21 O/V stage 1 operated at Akola end .L/O trip for remote end fault at Koradi end on receipt of DT signal.

9 400kV Koradi 400kV Koradi-K,khedaCkt-1

MSETCL (Y)

05-09-2012 07:30 06-09-2012 06:51 O/V stage 1 operated at Koradi end .L/O trip for remote end fault at K,kheda end on receipt of DT signal.

10 400kV Koradi 400kV Koradi-K,khedaCkt-2

MSETCL (Y)

05-09-2012 07:30 06-09-2012 06:14 O/V stage 1 operated at Koradi end .L/O trip for remote end fault at K,kheda end on receipt of DT signal.

11 400kV Koradi 400kV Koradi-Bhilai MSETCL (Y)

05-09-2012 04:18 05-09-2012 10:53 Inetially line tripped on reactor winding Temp high due to shorting/damage of TB.By passing above feature line recharged but tripped on O/V at both ends.The faulty replaced . Winding Temp high received due to shorting of TB on MB. There was no actual rise in Windg temp.(Bay/lines maintained by PGCIL)

12 400kV Khaparkheda 400kV Kh,kheda-Ch,pur

MSETCL (Y)

06-09-2012 02:35 06-09-2012 06:29 O/V stage 1 operated at K,kheda end .L/O trip for remote end fault at Ch.pur end on receipt of DT signal.

13 400kV Chandrapur 400kV Ch,pur-Parli-2 MSETCL (Y)

09-09-2012 17:31 10-09-2012 07:07 Transient R-N fault . It is reported that lightening stroke observed between Loc No.35-36 during tripping.


11-09-2012 03:36 11-09-2012 05:15 O/V stage 1 operated at Sarani end .L/O trip for remote end fault at Koradi end on receipt of DT signal.

15 400kV Koradi 400kV Koradi-IndiaBulls

MSETCL (Y)

04-10-2012 16:50 04-10-2012 17:19 Ckt tripped at Koradi end due to L/O trip for remote end fault on the receipt of DT signal from remote end.(Newly commissioned Line).PLCC Problem at IB end.


26-10-2012 13:55 26-10-2012 14:18 Transient Y-n fault .line A/R successfully at Koradi end and tripped at sarani end.(PGCIL Line)

17 400kV Bhilai 400KV Bhilai-Koradi

CSPTCL (Y)

05-09-2012 04:18 05-09-2012 10:56 Line tripped from both ends due to problem in Reactor at Koradi end.

18 400kV Bhilai 400KV Bhilai-Korba(W) Bank

CSPTCL (Y)

09-09-2012 12:15 09-09-2012 12:44 Line tripped from both ends due to normal tripping.

19 400kV Bhilai 400KV Bhilai- Ch,pur CSPTCL (Y)

29-09-2012 23:08 30-09-2012 10:17 Line tripped from both ends due to Over Voltage.

20 400kV Satpura S/S 400kV Sarani-Itarsi MPPGCL (Y)

02-08-2012 13:42 02-08-2012 18:28 Line tripped from both ends due to Over Voltage.

21 400kV Satpura S/S 400kV Sarani-Seoni MPPGCL (Y)

04-08-2012 22:45 04-08-2012 23:42 Line tripped on Bus Bar Diff zone-2, due to Sarni ISP Line C.B failure.

22 400kV Satpura S/S 400/220kV ICT MPPGCL (Y)

06-08-2012 04:52 06-08-2012 12:00 ICT tripped from both sides, due to fault at 220kV side B-Phof GT unit-3

23 400kV Satpura S/S 400kV Sarani-Koradi MPPGCL (Y)

07-08-2012 13:05 07-08-2012 14:20 Sarani end C.B tripped due to receipt of false DT code-3 from Sarani end carrier Panel.


07-08-2012 13:55 07-08-2012 19:07 Line tripped on C.B. pole discripency at Sarani end .Seoni end C.B. hand tripped . On checking Y-Ph C.B. Grp-A trip Ckt cable found faulty and short.The same was replaced.


25-08-2012 23:10 25-08-2012 23:34 Koradi end C.B tripped due to receipt of false DT code-3 from Sarani end carrier Panel.


11-09-2012 03:35 11-09-2012 05:15 Line tripped on receipt of DT from remote end,due to Koradi end O/V protection operated.


_ _ _ _ Delited

28 400 KV Birsinghpur 400KV Bir-Katni MPPGCL (Y)

19-11-2012 19:33 11-12-2012 10:34 The Line tripped at DEF on Y-Ph fault at 16.71 Kms from BRS end.

29 220kV TAPS 220kV TAPS-Vapi NPCIL (Y)

02-07-2012 13:05 02-07-2012 21:04 Transient Fault.

30 220kV TAPS 220kV TAPS-Borivali NPCIL (Y)

25-08-2012 12:51 25-08-2012 13:28 Transient Fault.

31 220kV TAPS 220kV TAPS-Bhilad NPCIL (Y)

30-08-2012 12:29 30-08-2012 13:10 Transient Fault.

32 220kV TAPS 220kV TAPS-Borivali NPCIL (Y)

02-10-2012 03:14 02-10-2012 14:08 Transient Fault.

Page1

(1) TRIPPINGS OF LINES / ICTS of MSETCL,CSPTCL,MPPGCL & NPCIL

33 400kV Mundra 400kV Mumndra-Limbdi#2

PGCILL (Y)

02-07-2012 04:20 02-07-2012 05:00 A/T on B‐N fault (foggy conditions in the salty area of Rann of Kutch)


PGCILL (Y)

02-07-2012 05:50 02-07-2012 05:53 A/T on Y‐N fault (foggy conditions in the salty area of Rann of Kutch)

35 400kV Mundra 400kV Mumndra-Bachau#1

PGCILL (Y)

02-07-2012 05:53 04-07-2012 01:24 A/T due to Bus Bar Protection Operation at Mundra end.

36 400kV Shujalpur 400kV Shujalpur-Nagda#1

PGCILL (Y)

03-07-2012 14:36 03-07-2012 14:36 A/R on R‐N fault.

37 400kV Damoh 400kV Damoh-Birsinghpur#2

PGCILL (Y)

03-07-2012 15:09 04-07-2012 16:21 A/T on Failure of B‐ph LA at Birsingpur (MPPTCL S/S).

38 400kV Gandhar 400kV Gandhar-Dehgam#1

PGCILL (Y)

03-07-2012 22:56 03-07-2012 22:56 A/R on B‐N fault.


PGCILL (Y)

03-07-2012 23:13 04-07-2012 18:00 A/T on Y‐N fault(Insulator string failure)

40 400kV Mundra 400kV Mundra-Bachau#1

PGCILL (Y)

04-07-2012 01:42 06-07-2012 12:44 A/T due to Bus Bar Protection Operation at Mundra CGPL.

41 400kV Mundra 400kV Mundra-Limbdi#1

PGCILL (Y)


42 400kV Bhachau 220kV Bachau-Ranch,pura#1

PGCILL (Y)


43 400kV Vindhyachal 400kV Vindhyachal-Jabalpur#2

PGCILL (Y)

05-07-2012 05:08 05-07-2012 05:08 A/R on Y‐N fault.


PGCILL (Y)

07-07-2012 07:46 07-07-2012 08:48 A/T on R‐N fault (foggy conditions in the salty area of Rann of Kutch)

45 400kV Indore 40kV Indore-Asoj#2 PGCILL (Y)

07-07-2012 16:37 08-07-2012 10:22 A/T on R‐N fault (Insulator Flashover)

46 400kV Khandwa 400kV Khandwa-Dhule#1

PGCILL (Y)

13-07-2012 05:12 13-07-2012 05:12 A/R on Y‐N fault.

47 400/220kV ICT BinaS/S

400/220kV ICT-1 PGCILL (Y)

13-07-2012 16:06 06-08-2012 22:38 A/T on operation of Bucholz & PRV

48 400kV Satna 40kV Satna-Bina PGCILL (Y)

23-07-2012 12:27 23-07-2012 12:27 A/R on Y‐N fault


PGCILL (Y)

24-07-2012 03:23 24-07-2012 08:24 A/T on Y‐B‐N fault (foggy conditions in the salty area of Rann of Kutch)


PGCILL (Y)



PGCILL (Y)



PGCILL (Y)



PGCILL (Y)



PGCILL (Y)



PGCILL (Y)



PGCILL (Y)

27-07-2012 06:23 27-07-2012 08:57 A/T on R‐Y‐B fault (foggy conditions in the salty area of Rann of Kutch)


PGCILL (Y)



PGCILL (Y)



PGCILL (Y)



PGCILL (Y)


61 400kV Itarsi 400kV Itarsi-Indore#2 PGCILL (Y)

29-07-2012 13:43 29-07-2012 19:44 A/T on R‐N fault (failure of E/W mid span Joint)


PGCILL (Y)



PGCILL (Y)



PGCILL (Y)



PGCILL (Y)



PGCILL (Y)



PGCILL (Y)

31-07-2012 02:33 31-07-2012 08:19 A/T on R‐Y‐N fault (foggy conditions in the salty area of Rann of Kutch)


PGCILL (Y)



PGCILL (Y)


70 400kV Bachau 400kV Bachau-Ranchodpura#1

PGCILL (Y)



PGCILL (Y)


Page2

(2) TRIPPINGS OF LINES / ICTS of PGCIL

72 400kV Baghau 400kV Bachau-Ranchodpura#1

PGCILL (Y)



04-08-2012 19:31 05-08-2012 12:26 A/T on R‐N fault (Insulator flash over).


PGCILL (Y)

05-08-2012 04:09 05-08-2012 12:27 A/T on receipt of DT from Mundra end


PGCILL (Y)



PGCILL (Y)



PGCILL (Y)



PGCILL (Y)

06-08-2012 05:42 06-08-2012 05:42 A/R on B‐N fault.


PGCILL (Y)



PGCILL (Y)


81 400kV Khandwa 40kV Khandwa-Dhule#2

PGCILL (Y)

07-08-2012 05:57 07-08-2012 05:57 A/R on Y‐N fault.


PGCILL (Y)

08-08-2012 04:15 08-08-2012 22:33 A/T on R‐Y fault (foggy conditions in the salty area of Rann of Kutch)


PGCILL (Y)

08-08-2012 04:15 08-08-2012 09:28 A/T on B‐R fault (foggy conditions in the salty area of Rann of Kutch)

84 400kV Satna 40kV Satna-Bina#2 PGCILL (Y)

08-08-2012 10:14 09-08-2012 10:14 A/T on B‐N fault (Insulator string failure)


08-08-2012 23:13 09-08-2012 13:53 A/T on B‐N fault (Insulator string failure)


PGCILL (Y)



PGCILL (Y)



PGCILL (Y)

10-08-2012 04:07 10-08-2012 08:38 A/T on Y‐B‐N fault (foggy conditions in the salty area of Rann of Kutch)


PGCILL (Y)



PGCILL (Y)


91 400/220kV ICT BinaS/S

400/220kV ICT-1 PGCILL (Y)

20-08-2012 14:30 21-08-2012 02:13 ICT A/T on operation on differential protection due to failure of 33kV Y‐ph LA.


21-08-2012 14:29 22-08-2012 09:40 A/T on B‐N fault. (B‐ph inner string failure)


PGCILL (Y)

22-08-2012 16:47 22-08-2012 21:00 A/T on R‐B fault


PGCILL (Y)

23-08-2012 09:19 23-08-2012 14:07 A/T on R‐B fault (Jumper snapping)


29-08-2012 08:50 29-08-2012 17:40 A/T on Y‐N fault.(Persisting fault)


PGCILL (Y)

07-09-2012 11:05 07-09-2012 15:09 A/T on R‐Y fault (Jumper failure)


PGCILL (Y)

11-09-2012 19:05 11-09-2012 19:44 A/T on R‐B fault.

98 400kV Bina 400kV Bina-Sujalpur#2 PGCILL (Y)

16-09-2012 04:40 16-09-2012 05:00 A/T at Bina end only on D/T received due to BPL PLCC mal operation.


22-09-2012 17:51 22-09-2012 10:55 A/T on Y‐N fault (Insulator String failure)


PGCILL (Y)

23-09-2012 17:59 23-09-2012 02:13 A/T on DT receipt due to reactor protection optd at V'chal end.Reactor corona ring problem. The Reactor is kept out for repair.


PGCILL (Y)

24-09-2012 12:01 24-09-2012 18:32 A/T due to failure of B‐Ph LA at JBP end.


26-09-2012 10:51 26-09-2012 21:56 A/T on B‐N fault (Insulator falshover)

103 400kV Bina 400kV Bina-Sujalpur#1 PGCILL (Y)

01-10-2012 22:55 01-10-2012 23:05 A/T due to operation of Reactor Protection at Sujalpur S/S.

104 400kV Satna 400kV satna-Bina#2 PGCILL (Y)

11-10-2012 17:51 11-10-2012 10:24 A/T on B‐N fault (Insulator flashover)

105 400kV Vindhyachal 400kV Vindhyachal-Satna#3

PGCILL (Y)

14-10-2012 12:57 14-10-2012 13:51 A/T on B‐N fault.(Persisting fault)

106 400kV Jabalpur 400kV Jab,pur-Itarsi#3 PGCILL (Y)

20-10-2012 03:02 20-10-2012 03:02 A/R on R‐N fault.

107 400kV Bachau 400kV Bachau-Ran,pura#1

PGCILL (Y)

29-10-2012 13:42 29-10-2012 13:42 A/R on B‐N fault


09-11-2012 04:00 09-11-2012 04:15 A/T on Y‐N fault.(Persisting fault)

109 400kV Mundra 400kV Mundra-Bachau#1

PGCILL (Y)

10-11-2012 12:00 10-11-2012 12:22 A/T on receipt of Direct Trip signal from CGPL Mundra end (BPL PLCC mal operation).

110 400kV Gandhar 400kV Gandhar-Navsari#1

PGCILL (Y)

19-11-2012 12:02 19-11-2012 12:40 A/T on R‐N fault (Sugarcane Burning)

111 400kV Gandhar 400kV Gandhar-Navsari#2

PGCILL (Y)

19-11-2012 12:02 19-11-2012 12:49 A/T on B‐N fault (Sugarcane Burning)

112 400kV Vindhyachal 400kV Vindhyachal-Satna#4

PGCILL (Y)

30-11-2012 00:32 30-11-2012 01:57 A/T on operation of Reactor Protection at Satna S/S.

Page3

116PCM ANNEXURE-3A

1 400KV Wardha 400KV Wardha ‐ Akola # 2

PGCILL (Y)

01-07-2012 14:48 01-07-2012 15:16 Line tripped at Wardha end only due to D/T received from Akola.

2 400KV Koradi 400KV Koradi‐Satpura

PGCILL (Y)

03-07-2012 22:55 03-07-2012 23:20 Line tripped due to problem in auto recloser at Satpura end.A/R successful at Koradi end

3 400KV Ranchi 400KV Ranchi ‐Sipat #

PGCILL (Y)

05-07-2012 06:49 05-07-2012 08:32 Line tripped due to DT received at Ranchi from NTPC sipat end.

4 220KV Korba(E) 220KV Korba(e)‐Budipadar # 3

PGCILL (Y)

05-07-2012 15:27 05-07-2012 15:37 Line tripped due to Bph‐earth fault at FL=128km from Korba end.

5 400KV Raigarh 400KV Raigarh‐SEL PGCILL (Y)

06-07-2012 05:28 06-07-2012 05:35 Line tripped due to overvoltage at Raigarh.

6 400KV Korba 400KV Korba‐Raipur # 4

PGCILL (Y)

06-07-2012 16:50 06-07-2012 16:50 Line A/R successfully from both ends on R‐E fault FL=248.5km from Raipur end.


13-07-2012 01:17 13-07-2012 01:25 Line tripped on overvoltage at Raigarh end.



9 400KV Wardha 400KV Wardha ‐ Mouda # 1

PGCILL (Y)

20-07-2012 16:37 20-07-2012 17:17 Line tripped on DT received from Mouda end during testing at Mouda end.

10 400KV Raipur 400KV Raipur‐Raigarh # 2

PGCILL (Y)


11 400KV Korba 400KV Korba‐Raipur # 4

PGCILL (Y)

21-07-2012 03:18 21-07-2012 03:18 Line A/R sucessfully from both ends. Y‐Ph‐E fault and 258km from Raipur end.

12 400KV Vindhyachal

400KV Vindhyachal‐Mahan

PGCILL (Y)

30-07-2012 03:39 30-07-2012 03:44 Line tripped due to Overvoltage.

13 400KV Raigarh 400KV Raigarh‐Rourkela # 1

PGCILL (Y)

31-07-2012 12:57 31-07-2012 13:10 Line tripped on receipt of Direct trip due to grid disturbace.

14 400KV Raigarh 400KV Raigarh‐Sterlite (SEL)

PGCILL (Y)



PGCILL (Y)

31-07-2012 12:57 31-07-2012 13:10 Line tripped on receipt of Direct trip due to grid grid disturbace.

16 400KV Raipur 400KV Raipur‐Sipat # 1

PGCILL (Y)


17 400KV Raipur 400KV Raipur‐Sipat # 2

PGCILL (Y)



PGCILL (Y)


19 400KV Ranchi 400KV Ranchi‐Sipat # 2

PGCILL (Y)



PGCILL (Y)

16-08-2012 03:34 16-08-2012 03:44 Line tripped on Y‐E fault , Zone‐1 F. L 65 Km from Raigarh end .

21 400KV Korba 400KV Korba‐ Mahan PGCILL (Y)

20-08-2012 11:31 20-08-2012 11:41 Line tripped on Bph‐e fault F/L= 27km from Mahan,

22 400KV Wardha 400KV Wardha‐Akola # 1

PGCILL (Y)

22-08-2012 11:54 22-08-2012 12:04 Line tripped on receipt of DT at Wardha due to over voltage at Akola end.

23 400KV Tarapur 400KV Tarapur ‐Padghe # 1

PGCILL (Y)

_ _ _ _ Delited

24 400KV Raigarh 400KV Raigarh‐SEL # 2

PGCILL (Y)

26-08-2012 03:17 26-08-2012 03:23 Line tripped due to phase to earth fault in LILO portion of SEL.


PGCILL (Y)

27-08-2012 03:16 27-08-2012 03:21 Line tripped due to phase to earth fault in LILO portion of SEL.


PGCILL (Y)

27-08-2012 04:04 27-08-2012 05:12 Line tripped due to Bus bar protection at M/s SEL end.


PGCILL (Y)

28-08-2012 03:51 28-08-2012 04:01Line tripped on over voltage at Raigarh end.


PGCILL (Y)

02-09-2012 06:41 02-09-2012 06:46Line tripped on over voltage at Raigarh.

29 400KV Wardha 400KV Wardha‐Akola # 2

PGCILL (Y)

02-09-2012 19:30 02-09-2012 19:35 Line tripped due to overvoltage at Wardha end

30 400KV Raipur 400KV Raipur‐KSK (LILO of 400kv Raipur‐Raigarh # 3 )

PGCILL (Y)

03-09-2012 23:21 03-09-2012 23:26 Line tripped due to over‐voltage at Raipur end

Page1

(1) TRIPPINGS OF LINES / ICTS PGCIL (WRTS-I)


PGCILL (Y)

04-09-2012 01:04 04-09-2012 01:09 Line tripped due to over‐voltage at Raipur end

32 400KV Bhilai 400KV Bhilai‐ Seoni PGCILL (Y)

05-09-2012 01:33 05-09-2012 01:38 Tripped on OverVoltage at Bhilai.

33 400KV Korba 400KV Korba ‐ Mahan

PGCILL (Y)

05-09-2012 13:34 05-09-2012 15:47 Line tripped on R‐B fault at 66km from Mahan 165 Kms from NTPC Korba due to Tree fault.


PGCILL (Y)

_ _ _ _ Delited


PGCILL (Y)

_ _ _ _ Delited

36 400KV Raigarh 400KV Raigarh ‐SEL # 1

PGCILL (Y)

_ _ _ _ Delited


PGCILL (Y)

_ _ _ _ Delited


PGCILL (Y)

_ _ _ _ Delited


PGCILL (Y)

09-09-2012 04:08 09-09-2012 04:13 Line tripped due to Overvolatge at Raigarh end

40 400kV Raigarh 400kV Raigarh‐SEL # 1

PGCILL (Y)

10-09-2012 12:18 10-09-2012 12:28 Line tripped due to Yph‐e fault in the LILO section of SEL.Busbar protection operated

41 400KV Korba 400KV Korba‐Bhatapara

PGCILL (Y)

11-09-2012 00:05 11-09-2012 04:32 Line tripped due to Bus fault at Korba(NTPC) switchyard.DT recived at Bhatapara.

42 400KV Raipur 400KV Raipur‐Korba # 4

PGCILL (Y)

11-09-2012 00:05 11-09-2012 00:15 Line tripped due to Bus fault at Korba(NTPC) switchyard.

43 400KV Raipur 400KV Raipur‐KSK PGCILL (Y)

13-09-2012 05:27 13-09-2012 05:27 Line auto reclose succcessfull at both ends on B‐E fault , fault location 89.88Km from

44 400KV Raigarh 400KV Raigarh‐SEL#2

PGCILL (Y)

14-09-2012 03:57 14-09-2012 04:02 Line tripped due to over voltage.

45 765KV Seoni 765KV Seoni ‐ Bilaspur# 1

PGCILL (Y)

14-09-2012 18:59 14-09-2012 19:04 Line tripped due to O/V , following the fault at Sipat(NTPC)

46 765KV Seoni 765KV Seoni ‐ Bilaspur# 2

PGCILL (Y)

14-09-2012 19:02 14-09-2012 19:07 Line tripped due to/ OV , following the fault at Sipat(NTPC)

47 765KV Sipat‐ Bilaspur

765KV Sipat‐ Bilaspur# 1

PGCILL (Y)

14-09-2012 18:59 14-09-2012 19:07 Line tripped due to relay Mal‐operation (REF operated at NTPC Sipat, following the Bus‐fault.

48 765KV Sipat‐ Bilaspur

765KV Sipat‐ Bilaspur# 2

PGCILL (Y)

14-09-2012 19:02 14-09-2012 19:07 Line tripped due to OV , following the fault at Sipat(NTPC)

49 400KV Raigarh 400KV Raigarh‐SEL#1

PGCILL (Y)

15-09-2012 03:46 15-09-2012 03:51 Line tripped due to OV at Raigarh

50 400KV Wardha‐Mouda

400KV Wardha‐Mouda # 1

PGCILL (Y)

22-09-2012 16:13 22-09-2012 19:10 Line tripped on receipt of Direct trip at Wardha from NTPC Mouda end.

51 400KV Raigarh 400KV Raigarh-Rourkela # 3

PGCILL (Y)

16-09-2012 12:45 21-10-2012 17:25 Line tripped on Yph‐Bph fault (Tower collapse ) in Rourkela (ER) portion .FL ‐ 135 KM from Raigarh end

52 400KV Raigarh 400KV Raigarh-SEL # 2 (lilo of Raigarh-Rourkela # 4)

PGCILL (Y)

02-10-2012 18:02 02-10-2012 18:12 Line tripped due to overvoltage at Raigarh end.

53 400KV Tarapur 400KV Tarapur‐Boisar # 2

PGCILL (Y)

06-10-2012 18:24 06-10-2012 19:21 Line tripped on fault only at Tarapur end .A/R successful at Boisar end.

54 400KV Tarapur 400KV Tarapur‐Padghe # 1

PGCILL (Y)

07-10-2012 16:26 07-10-2012 17:02 Line tripped only at Tarapur end due to A/R kept off at tarapur generating station end , A/R successful at padghe end on Bph‐E fault (F.L. 14 KM from Padge and 72 KM from Tarapur )

55 400KV Kolhapur

400KV Kolhapur‐Mapusa # 1

PGCILL (Y)

08-10-2012 04:05 08-10-2012 04:15 Line tripped due to overvoltage at Kolhapur end.DT received at Mapusa.

56 400KV Wardha 400KV Wardha ‐Akola # 1

PGCILL (Y)

08-10-2012 09:54 08-10-2012 09:59 Line tripped due to o/v at wardha end.

57 400KV Wardha 400KV Wardha ‐Mauda # 1

PGCILL (Y)

08-10-2012 09:54 08-10-2012 09:59 Line tripped due to o/v at wardha end

58 400KV Boisar 400KV Boisar‐Padge PGCILL (Y)

14-10-2012 13:58 14-10-2012 13:58 Line was Auto Reclosure successful on Rph‐E fault . F.L: 28.2 KM from Boisar end .

59 400KV Kolhapur

400KV Kolhapur ‐Mapusa # 2

PGCILL (Y)

24-10-2012 17:05 24-10-2012 17:10 Line tripped due to overvoltage at Kolhapur end .

60 400KV Raigarh 400KV Raigarh ‐ KSK (Lilo of Raipur‐ Raigarh # 3)

PGCILL (Y)

26-10-2012 21:48 26-10-2012 21:58 Line tripped on Overvoltage at Raigarh end

61 400KV Koradi 400KV Koradi‐Satpura

PGCILL (Y)

26-10-2012 13:54 26-10-2012 14:18 Line autoreclosed sucessfully from Koradi end Yph E fault . Fault location 95Km from Koradi. But tripped at Satpura end due to A/R problem.

Page 2

62 400KV Seoni 400KV Seoni‐Satpura PGCILL (Y)

26-10-2012 13:55 26-10-2012 13:55 Autoreclosed sucessfully from both ends at 13:55hrs. Yph E fault . Fault location from seoni 33.6Km.

63 400KV Seoni 400KV Seoni‐Bhilai PGCILL (Y)

30-10-2012 12:22 30-10-2012 16:07 Line tripped on receipt of DT at seoni end from Bhilai due to bus fault at Bhilai end .

64 400KV Bhadrawati

400KV Bhadrawati‐Bhilai

PGCILL (Y)

30-10-2012 12:22 30-10-2012 13:11 Line tripped only at Bhadrawati end on receipt of DT from Bhilai due to bus fault at Bhilai end .

65 400KV Raigarh 400KV Raigarh ‐ KSK (Lilo of Raipur‐ Raigarh # 3)

PGCILL (Y)

01-11-2012 22:22 01-11-2012 22:32Line tripped due to Over Voltage at KSK end & DT receive at Raigarh end

66 400KV Raigarh 400KV Raigarh ‐ KSK(Lilo of Raipur‐

PGCILL (Y)

02-11-2012 21:14 02-11-2012 21:24 Line tripped due to Over Voltage at KSK end & DT receive at Raigarh end

67 400KV Raipur 400KV Raipur ‐ Raigarh # 2

PGCILL (Y)

11-11-2012 02:30 11-11-2012 02:40Line tripped on Overvoltage at Raigarh end

68 400KV Raigarh 400KV Raigarh‐ SEL # 1 (lilo of Raigarh‐Rourkela # 2 )

PGCILL (Y)

11-11-2012 02:30 11-11-2012 02:40

Line tripped on Overvoltage at Raigarh end

69 400KV Raigarh 400KV Raigarh‐ SEL # 2 (lilo of Raigarh‐Rourkela # 4 )

PGCILL (Y)

11-11-2012 02:30 11-11-2012 02:40

Line tripped on Overvoltage at Raigarh end

70 400kv Raigarh 400kv Raigarh‐Rourkela # 3

PGCILL (Y)

13-11-2012 11:49 13-11-2012 11:49Line autoreclosed successfully on B‐E fault , fault location 68Km from Rourkela end.

71 400KV Kolhapur 400KV Kolhapur ‐Mapusa # 2

PGCILL (Y)

13-11-2012 16:30 13-11-2012 16:35 Line tripped on overvoltage at kolhapur end , DT received at Mapusa end .

72 400KV Kolhapur 400KV Kolhapur ‐Mapusa # 1

PGCILL (Y)

19-11-2012 00:00 19-11-2012 00:10 Line was tripped on overvoltage at Kolhapur end.

73 400 KV Wardha 400 KV Wardha ‐ Mauda #1

PGCILL (Y)

19-11-2012 21:37 19-11-2012 21:47Line tripped due to overvoltage at Mauda end

74 400kV Raigarh 400kV Raigarh ‐ KSK PGCILL (Y)

29-11-2012 03:09 29-11-2012 03:14 tripped due to Overvoltage at Raigarh ,DT sent to KSK end

75 765Kv Seoni 765Kv Seoni ‐ Wardha # 1

PGCILL (Y)

29-11-2012 21:06 29-11-2012 21:11Line tripped due on Over Voltage

76 400kv Wardha 400kv Wardha‐ Parli # 1

PGCILL (Y)

29-11-2012 21:10 29-11-201221:27 Line tripped due on Over Voltage

77 400kv Wardha 400kv Wardha‐ Akola # 1

PGCILL (Y)


78 400kv Wardha 400kv Wardha‐ Moudha # 1

PGCILL (Y)


79 220kV Tarapur 220kV Tarapur‐Boiser

PGCILL (Y)

03-12-2012 11:03 03-12-2012 18:05 Line tripped at Tarapur end only but autoreclosed successfully on Yph‐e fault at boiser, F.l= 16.8km boiser end, 94.3km from tarapur end


PGCILL (Y)

03-12-2012 14:24 03-12-2012 14:29 line tripped due to Overvolatage at Raigarh end


PGCILL (Y)

03-12-2012 21:24 03-12-2012 21:29 line tripped due to Overvolatage at Raigarh end


PGCILL (Y)

05-12-2012 21:54 05-12-2012 22:04 Line tripped on overoveltage at Raigarh end.

83 400KV Raipur 400KV Raipur‐Raigarh ‐2

PGCILL (Y)


84 400KV Raigarh 400KV Raigarh ‐sterlite # 2

PGCILL (Y)


85 400KV Korba 400KV Korba‐Raipur‐3

PGCILL (Y)

12-12-2012 01:21 12-12-2012 01:21 Line Auto reclosed successful at both ends on R‐E fault(Zone‐2) , F.L 236KM from Raipur

86 400KV Raigarh 400KV Raigarh ‐KSK. PGCILL (Y)

12-12-2012 02:24 12-12-2012 02:29 Line tripped on overvoltage only at Raigarh end.

87 400KV Raigarh 400KV Raigarh ‐sterlite # 2

PGCILL (Y)


88 400KV Wardha 400KV Wardha‐Akola‐1

PGCILL (Y)

13-12-2012 21:40 14-12-2012 05:08 Line tripped due to over voltage.

89 400KV Raipur 400KV Raipur‐Raigarh‐1

PGCILL (Y)


Page3

116PCM ANNEXURE-3B

1 400KV SGTPS, Substation, Birsinghpur

400KV Birsinghpur‐Damoh Line‐II(PGCIL feeder)

MPPGCL (Y)

03‐07‐2012 15:09 - BRS end – B Phase LA failed, Dist. /DEF‐B, 21 .1, 21.2, L/O relay, 86.1//86.2Damoh end – Dist. /DEF‐B, L/O Relay‐86 (i) M1 (REL‐670), Dist. 218.7Km (ii) M2(Siprotec‐A52) Not optd.


400KV Birsinghpur‐Damoh Line‐I

MPPGCL (Y)

03-07-2012 15:11 03-07-2012 22:55 BRS end – Dist. /DEF‐B, 21M1, 21M2, L/O relay, 86A//86BDamoh end – Dist. /DEF‐B, L/O Relay‐86 (i) M1 (REL‐670) (ii) M2(Siprotec‐A52)

3 400KV STPS Substation, Sarni.

400 KV Sarni‐ Koradi Line

MPPGCL (Y)

03-07-2012 22:55 03-07-2012 23:02 Sarni end –(A) Main‐I protection (5SA522) , Trip R‐ Ph. Trip Zone‐1, Dist. Pick up, Fault L1 – E=39.4%, Dist = 58.8 Km, Trip Relay 86R. (B) Main‐2 prot.,(Micom P‐442) ‐ R‐Ph. Trip, Zone‐1 Trip, CS, Fault L1 – E=59.53 Km, Trip Relay 86RX. (C) Auto Reclose lockout: 186A, 186BRemote end –(A) Main‐1 Prot. (REL‐670) Trip R‐Ph, GT, Open R‐phase, CR Trip ZM‐1, A/R, Start ZM‐2, Start ZM‐3, Fault Locator L1‐N = 58%, Trip Relay 86R. (B) Main‐2 prot.,(Micom P‐442) ‐ Start‐AN, Trip, Phaser‐A, Trip Zone‐1 Fault Loc. = 85.07 Km (C) Auto reclose optd.


400 KV Sarni‐ I.S.P Line

MPPGCL (Y)

30-07-2012 02:33 30-07-2012 03:42 Sarni end – Ch‐1/2, Code ‐1 recd. Direct trip, Gr. A/B L/O optd. Remote end – Main‐1 Prot. (REL‐521) – O/V 1st stage optd., Group – A/B , 3‐Ph trip, GT, Trip R, Y, B‐Ph, Trip‐ TOV, A/R block., Ch‐I/II direct trip sent


400 KV Sarni‐ I.S.P Line

MPPGCL (Y)

31-07-2012 13:00 31-07-2012 14:43 Sarni end – Ch‐1/2, Code ‐1 recd. Direct trip, Gr. A/B L/O optd.Remote end – Main‐1 Prot. (REL‐521) – O/V 1st stage optd., Group – A/B , 3‐Ph trip, GT, Trip R, Y, B‐Ph, Trip‐ TOV, A/R block., Ch‐I/II direct trip sent


400 KV Sarni‐ I.S.P Line MPPGCL (Y)

04-08-2012 22:45 14-08-2012 19:45 Sarni end – C.B. Gas Pressure 1st & IInd stage optd. CB Trip Coil A&B Breaker Poles damaged. Ch‐1/2, Code ‐1 recd. Direct trip, Gr. A/B L/O optd.Remote end – Nil



06-10-2012 12:05 06-10-2012 13:04 Sarni end – Code ‐1 recd. Direct trip, Gr. A/B L/O optd.Remote end – (i) Main –I Prot. optd.(REL 521, O/V 1st stage optd., Gr. A/B 3 Ph. trip, Ch‐I/II Direct trip send (ii) Main‐1 Prot. (REL‐521), GT, Trip R,Y,B Ph, Trip‐ TOV, A/R block



09-10-2012 12:13 09-10-2012 12:38 Sarni end – Ch‐1/2, Code‐1 recd. Direct trip, Gr. A/B L/O optd.Remote end – (i) Main –I Prot. optd.(REL 521, O/V 1st stage optd., Gr. A/B 3 Ph. trip, Ch‐I/II Direct trip send (ii) Main‐1 Prot. (REL‐521), GT, Trip R,Y,B Ph, Trip‐ TOV, A/R block

Page 1

(2) TRIPPINGS OF LINES / ICTS, MPPGCL


400 KV Sarni‐ Koradi Line

MPPGCL (Y)

26-10-2012 13:55 26-10-2012 14:18 Sarni end –(A) Distance protection Main‐I (5SA522) , Distance protection Main‐2 prot.,(Micom P‐442) ‐, A/R L/O optd. (B) Main‐I (5SA522) – Trip Y Ph. Trip Zone‐1, Distance Pick up, Fault LS‐E=27.1%, dist = 40.4 m, Trip Relay: 86Y Main‐2 prot.,(Micom P‐442) ‐, – B Ph. Trip Zone‐1, CS, Fault L2‐E=39.33 Km, , Trip Relay: 86YX., A/R , 186A, 186B.

Remote end –(A) Distance protection Main‐I optd (REL‐670) Distance protection Main‐2 optd. (Micom P‐442), A/R optd. (B) Main‐I prot. (REL‐670) Trip Y Ph. GT, open Y Ph, CR, Trip ZM‐1, A/R Start ZM‐2 Start,ZM‐3, Fault Locator L2‐N = 64% trip relay 86R. , Main‐2 prot.,(Micom P‐442) – Start‐BN, Trip ase‐B, Trip Zone‐1, Fault loc. 95.06 Km.


220KV BRS‐ Sukha MPPGCL (N)

04-07-2012 19:16 04-07-2012 19:54 BRS end – Z1 Tripped L3‐N dist. 119 Km, ARR, 186A, 186B Sukha end – DPR opetrate CN Tripped. ABC, Z1 FTI – distance 84 Km, 47%


220KV BRS‐AMK MPPGCL (N)

15-07-2012 19:04 15-07-2012 20:08 BRS end – DPR, A Phase, Z1 ARR, 186A, 186BAmk end – Relay operated DPR, A Ph, Z1, ARR, 186A, 186B, dist. 76.42 Km


220KV BRS‐ Satna MPPGCL (N)

22-07-2012 22:21 22-07-2012 22:23 BRS end – A Phase, Z1, 186A, 186B, Satna end – A Phase N, ARR, Z1, 179.2Km, 78%



24-07-2012 11:02 24-07-2012 11:04 BRS end – Relay operated C Phase Z1 Satna end –C Phase Tripped Z1, 167.4 Km, 73%



29-07-2012 08:42 29-07-2012 08:48 BRS end – Tripped A Phase, Z1, ARR, 186A, 186BSatna end – Tripped A Phase, Z1, 146.5 Km, 64%



06-08-2012 12:22 06-08-2012 12:36 BRS end – DPR, R Phase N. LIN 186A, 186B 155 Km.Sukha end – Phase AN, Z1, FT‐1 tripped ABC, 26.7 Km, 16%



08-08-2012 11:15 08-08-2012 11:26 BRS end – ARR, 186A, 186B, A/R, L/O Air pressure low main distance DRR Phase CZSatna end – A/RR, 186A, 186B, Phase, C Z1, 69 Km, 30%



19-08-2012 10:05 19-08-2012 10:45 BRS end – Z1, R Phase A/R, 186A, 186B, 96.0 KmSukha end – DPR, A6A DCZ1, FT1, 84.1 Km 49% main protection ABC



27-08-2012 12:05 27-08-2012 18:04 BRS end – DPR, Z1, R Phase, 186A, 186B, 68.8 Km, 48%Sukha end – Healthy



28-08-2012 12:17 28-08-2012 12:35 BRS end – DPR, Z1, 186A, 186B, 128 Km.Sukha end – DPR optd., A‐N tripped ABC Z1, FT‐1, 41.9 Km



06-09-2012 15:37 06-09-2012 15:56 BRS end – Auto reclose , 186A, 186B, DPR, R Phase NeutralSukha end – DPR optd., Phase AN, Z1, FTI trip, ABC 79.3 Km, 47% main pressure trip ABC

Page 2


220KV BRS‐Pali Inter Connecetor‐4

MPPGCL (N)

09-09-2012 11:04 09-09-2012 12:06 BRS end – A Phase, DPR, Auto reclose, 186A, 186BPali end ‐ Phase AN tripped ABC, Z1, FT1, 08 Km 36%



11-09-2012 15:35 12-09-2012 11:19 BRS end – Tripped at Z1, B, C Phase, 186A, 186BSatna end –Healthy



MPPGCL (N)

18-09-2012 12:12 18-09-2012 12:58 BRS end – Tripped on O/c E/F, ARR, 186A, 186BPali end ‐ A Phase Z1, 5.41 Km



MPPGCL (N)

18-09-2012 12:12 18-09-2012 12:54 BRS end – 67 NX, E/F Relay, ARR, 186A, 186BPali end ‐ Healthy



19-09-2012 11:45 19-09-2012 12:03 BRS end – C Phase, Z1, ARR, 186A, 186BSatna end –C Phase, Z1, 80.5 Km, 35%



23-09-2012 04:03 23-09-2012 16:51 BRS end – DRR, Z1, B Phase, 186A, 186BSatna end –Tripped Z1, B Phase, 89.1 Km, 39%



23-09-2012 11:43 23-09-2012 12:03 BRS end – AB Phase, Z1, ARR, 186A, 186B, 90.1 KmSukha end – AB Phase, Z1, SP trip ABC 67.7 Km, 41% Main Protection relay trip ABB



01-10-2012 15:07 01-10-2012 16:45 BRS end – Auto reclose , 186A, 186B, DPR, C Phase, Z1, 39.6 Km.Sukha end – DPR operate Phase C, Z1, FTI trip, 114 Km, 68%



05-10-2012 13:45 05-10-2012 18:25 BRS end – Auto reclose , 186A, 186B, DPR, R Phase, Neutral, Z2Sukha end – DPR operate Phase ABC, Z2, FTI trip, ABC



07-10-2012 12:05 07-10-2012 17:21 BRS end – Auto reclose , 186A, 186B, DPR, RY Phase, Neutral, Z1Sukha end – DPR operate Phase AB, Z1, FTI trip, ABC 21.3 Km, 13%



12-10-2012 17:03 12-10-2012 17:22 BRS end – Auto reclose , 186A, 186B, DPR, R Phase, Neutral, Z1, 94.6 KMSukha end – DPR operate Phase A, Z1, FTI trip, ABC 80.3 Km

32 220KV STPS, Substation, Sarni.38

220KV Sarni‐Pandhurna

MPPGCL (N)

01-07-2012 17:08 01-07-2012 17:46 Sarni ‐ PAT, PE, PTaw, PSWPandhurna end – E/F “B” Ph. Zone‐1

33 220KV STPS, Substation, Sarni.


MPPGCL (N)

29-08-2012 12:05 29-08-2012 13:49 Sarni ‐ PAT, PE, PTaw, PSW

Pandhurna end – O/C & E/F “B” Ph. Gen. trip



MPPGCL (N)

_ _ _ _ Delited

Page 3


Sarni S/s MPPGCL (N)

_ _ _ _ Delited


220KV Sarni‐Handiya MPPGCL (N)

_ _ _ _ Delited


220KV Sarni‐Itarsi No.II MPPGCL (N)

_ _ _ _ Delited


220KV Sarni‐Itarsi No.III

MPPGCL (N)

_ _ _ _ Delited

39 220KV ATPS, Substation, Chachai

220KV Chachai‐Sidhi Feeder

MPPGCL (Y)

01-07-2012 11:37 01-07-2012 11:56 ATPS ‐ B,C Phase , Zone‐1, Trip ABC, 86xRemote end – Trip ABC, Zone‐1, FT


220KV Chachai‐Sukha Feeder

MPPGCL (Y)

04-07-2012 18:15 07-04-2012 19:56 ATPS ‐ C Phase, Zone‐1, 186A,186B,DPR TripRemote end – C‐N Phase, Zone1,


220KV Chachai‐ Birsinghpur Feeder No3

MPPGCL (Y)

15-07-2012 19:04 15-07-2012 20:08 ATPS ‐ A Phase, Zone‐1, 86BX, Trip ABCRemote end – A Phase, Zone‐I, 186A, 186B



MPPGCL (Y)

22-07-2012 12:49 22-07-2012 13:04 ATPS ‐ A Phase, Zone‐1, 186A,186BRemote end – A Phase, Zone1, FT1 Trip


220KV Chachai‐Jabalpur Feeder No2

MPPGCL (Y)

29-07-2012 20:33 29-07-2012 20:39 ATPS ‐ A Phase, Z‐1, 86XRemote end – A‐N Phase, Zone‐2, DPR Optd., Trip ABC



MPPGCL (Y)

05-08-2012 19:02 05-08-2012 19:48 ATPS ‐ A Phase , Zone‐1, 86m1A, 86m2ARemote end – A‐N Phase, Zone‐1, SOTF, FTI Trip



MPPGCL (Y)

06-08-2012 04:55 06-08-2012 05:09 ATPS ‐ A Ph., Zone‐1, DPR Optd, L/ORemote end – A‐N Phase, Zone‐1



MPPGCL (Y)

11-08-2012 23:02 11-08-2012 23:03 ATPS ‐ CB lock out, A Phase, Zone‐1Remote end – A Phase, Autoreclose Optd., Zone‐1



MPPGCL (Y)

13-08-2012 19:33 13-08-2012 19:47 ATPS ‐ CB lock out, C Phase, Zone‐1, 86XRemote end – C‐N Phase, Zone‐1



MPPGCL (Y)

13-08-2012 22:02 13-08-2012 22:35 ATPS ‐ CB lock out, C Phase, Zone‐1, 86X, 80FRemote end – C‐N Phase, Zone‐1


220KV Chachai‐Birsinghpur Feeder No.2

MPPGCL (Y)

27-08-2012 14:37 27-08-2012 15:58 ATPS ‐ A Phase, Zone‐1, 186A, 186BRemote end – R Phase, Zone‐I, 186A, 186B


220KV Chachai‐Kotmikala Feeder No.1

MPPGCL (Y)

29-08-2012 20:04 29-08-2012 21:03 ATPS ‐ ABC Phase, Z1,186A,1 86B.Remote end – Nil



MPPGCL (Y)

01-09-2012 18:33 01-09-2012 18:53 ATPS ‐ A Phase, Zone‐1, Trip ABCRemote end – A Phase, Zone‐I, 186A, 186B



MPPGCL (Y)

06-09-2012 19:45 06-09-2012 20:51 ATPS ‐ A Phase , Zone‐1, 86M1A, 86M2ARemote end – A‐N, Zone‐1, SOTF, FTI



MPPGCL (Y)

06-09-2012 21:24 07-09-2012 12:17 ATPS ‐ A Phase , Zone‐1, 86M1A, 86M2ARemote end – A‐N, Zone‐1, SOTF, FTI



MPPGCL (Y)

08-09-2012 21:56 08-09-2012 23:01 ATPS ‐ AB‐N Phase , Trip ABC, Zone‐1, 86A, 86B, 30B, E/F.Remote end – Phase ABN, Trip ABC, Zone‐1, SOTF, FTI



MPPGCL (Y)

09-09-2012 10:33 09-09-2012 10:05 ATPS ‐ Trip ABC Phase, Zone‐3, L/O, 186A, 186B, 86A, 86B, 86CRemote end – Nil

Page 4



MPPGCL (Y)

09-09-2012 10:33 09-09-2012 10:55 ATPS ‐ Trip ABC, VT fail, CB Lock Out, DPR, 86X,86Remote end – Nil



MPPGCL (Y)

10-09-2012 18:19 10-09-2012 19.07 ATPS ‐ Trip ABC, Zone‐2, Phase AN.Remote end – A Phase, Zone‐I, 186A, 186B



MPPGCL (Y)

10-09-2012 18.23 11-09-2012 11:11 ATPS ‐ Trip ABC,Zone‐1, 186A, 186B. Remote end – Phase BC, Zone‐1, FT1



MPPGCL (Y)

10-09-2012 18.23 10-09-2012 18:55 ATPS ‐ B Phase, Zone‐1,86B, 86CRemote end – B Phase, Zone‐I, 186A, 186B



MPPGCL (Y)

11-09-2012 23:01 11-09-2012 23:36 ATPS ‐ Trip ABC, Zone‐1, DPRRemote end –Trip ABC, Zone‐1, SOTF, FTI


220KV Chachai‐ Sukha Feeder

MPPGCL (Y)

18-09-2012 13:04 18-09-2012 14:02 ATPS ‐ A Phase, 186A, 186B DPR Optd., L/O.Remote end – A‐N Phase, Zone‐2, DPR Optd., 2X, FT1



MPPGCL (Y)

23-09-2012 21:53 26-09-2012 22:25 ATPS ‐ A Phase, Zone‐1,186A, 186B, DPR Trip, Bkr L/O.Remote end – A Phase, Zone‐2, 186A, 186B



MPPGCL (Y)

24-09-2012 03:05 24-09-2012 03:58 ATPS ‐ B Phase, Zone‐1, CB Lock Out, DPR Optd., 86X.Remote end – B‐N Phase, Zone‐1, DPR Optd., A/R, FTI



MPPGCL (Y)

28-09-2012 12:01 28-09-2012 12:19 ATPS ‐ B Phase, Zone‐1, DPR Optd., CB L/O, 86XRemote end – Nil.



MPPGCL (Y)

29-09-2012 22:11 29-09-2012 22:02 ATPS ‐ A Phase, Zone‐1, DPR Optd., CB L/O Remote end – A Phase‐N. A/R, DPR Optd.



MPPGCL (Y)

03-10-2012 12:11 03-10-2012 12:23 ATPS ‐ Phase BC‐N, Z‐1 , Auto Trip DPR Optd. 86B, 50C, 70XRemote end – Phase CN, Z‐1, Trip ABC, SOTF, FTI



MPPGCL (Y)

03-10-2012 12:39 03-10-2012 13:01 ATPS ‐ Phase BC, Z‐1 , 86B, 59BC, DPR optd.Remote end – Z‐1, SOTF, FT



MPPGCL (Y)

05-10-2012 11:33 05-10-2012 13:58 ATPS ‐ C Phase, DPR Lock out,, 186A, 186BRemote end – C Phase, Zone‐1, 186A, 186B



MPPGCL (Y)

08-10-2012 20:03 08-10-2012 20:22 ATPS ‐ A Ph, Z‐1 , 86M1A, 86M2ARemote end – A‐N, Z‐1, SOTF, FTI



MPPGCL (Y)

12-10-2012 02:31 12-10-2012 02:46 ATPS ‐ C Phase, 186A, 186B Lock out, Z‐1Remote end – Phase C‐N, Z‐1, DPR Optd, FT‐1, Trip ABC



MPPGCL (Y)

15-10-2012 17:05 15-10-2012 17:17 ATPS ‐ Phase ABC, Z‐1, DPR Optd., CB Lock outRemote end – Trip ABC, Phase BC, DPR Optd., CRT, FT1, Z‐2



MPPGCL (Y)

21-10-2012 10:59 21-10-2012 11:01 ATPS ‐ Pase BC‐N, Z‐1Remote end – C‐N, Z‐1, SOTF, FT1


220KV Chachai‐ Kotmikala Feeder No.2

MPPGCL (Y)

26-10-2012 13:35 26-10-2012 13:57 ATPS ‐ C Phase, Zone‐1, 186A, 186B, Breaker Trip Remote end – DPR Optd, 21XB

Page 5

Annexure-IV Status of implementation in WR on Recommendations of Report on Grid disturbance on 30th and 31st July as on 10.02.2013

No. Time Subject/Description Action taken

Frame 9.1.1 1 Year There is a need to review protection schemes. This

Committee concurs with recommendation of previous enquiry committees that a thorough third partyprotection audit need to be carried out in time boundmanner. This exercise should be repeated periodically and monitored by RPCs.

RPCs, CTU, STUsGETCO: Completed all 400 kV s/s in 2010 through M/s Voltech Engg. MSETCL : Through PRDC completed 80/116 important s/s in Jan-13. Rest will be completed by Feb-13. NTPC : Internal PA completed. Completed at VSTPS through PGCIL. Requested PGCIL to carry out PA at Sipat, Korba, Kawas & Gandhar MPPTCL : PA internal group from SLDC, NHDC, MPPTCL, MPPGCL formed. 3 s/s(Bhopal, Indore & Nagda) completed in Jan-13. Plan for 4 thermal, 3 hydro and 2 400 kV s/s in Feb-13 and other hydel stations and s/s in Mar-13. Regarding third party audit tending work is being taken up. PGCIL : 1 s/s at Bina completed in Aug-2012 by CPRI. A group of protection Engineers from WRLDC, WR-I & WR-II carried out PA at Gwalior in Dec-12, Pirana, Damoh, Satna, Seoni, Bhadravati, raigarh, Vapi, Pune in Jan-13. JP Bina/JPL: PGCIL to carry out PA CSPTCL : Planned for internal PA. Requested to carry out third party PA. Rinfra :10 stations identified for PA through PRDC. Target for completion-30.06.13 NPCIL : Internal PA to be carried out by Feb-13. CGPL: PA carried out on 22/23.01.2013 through revolving group. WRPC : Revolving group formed, PA to be carried out based on requests received. Requests for PA received from NPCIL and CSPTCL.

9.1.2 Immediate Till protection audit is taken up, there is need to take immediate review of zone-3 philosophy in particular. Techniques are available to modify characteristics of the relay so that it can distinguish between load encroachment and faults. These techniques and other alternatives should be explored immediately.

RPCs, CTU, STUsPower Swing MSETCL : All zones blocked for 2 Sec NTPC : All zones blocked for 2 Sec GETCO :zone-3 blocked as per CBIP 274 manual Load Encroachment Approach : Following two approaches are identified. (i) Shaping of Z-3 by distinguishing between load and

line angles wherever the relay supports this feature. (ii) Z-3 adaptive protection by sensing the zero sequence

component wherever the relay supports this feature. In the 116th PCM utilities were requested to judiciously adopt the settings for Z-3 where ever the relay supports these feature.

9.1.3 1 year The application of synchrophasor measurements fromPMUs should be explored for protection systems. There is also an urgent need to deploy Special Protection System (SPS) in critical transmission elements. Also there is need to make already approved SPS operational.

RPCs, CTUPMUs under pilot project installed at Raipur, Bhadravati, Jabalpur, Itarsi. PMUs at KSTPS, VSTPS and SSTPS is planned to be installed by WRLDC as discussed in the meeting held on 21.09.12. In Maharashtra 17 PMUs have been installed. URTDSM is being implemented by PGCIL. It is decided to procure 30% of PMU through indigenous sources as agreed in 35th SCM of WR. MSETCL : Location for 50 PMUs have been identified through IIT, Mumbai. To be integrated with URTDSM. CGPL : PMUs is planned to be installed by WRLDC

9.1.4 1 Month A complete independent audit of time synchronization ofDRs, ELs and PMUs should be carried out

Generators, CTU, STUs Status of time synchronization awaited from STUs

9.2.1 1 Month Frequency band needs to be further tightened andbrought close to 50 Hz. POSOCO may file an urgency application in Supreme Court for early resolution of the issue in view of the recent grid disturbances.

POSOCO

9.2.2 3 months A review of UI mechanism should be carried out in viewof its impact on recent grid disturbances. Frequency control through UI may be phased out in a time bound manner and Generation reserves/Ancillary services may be used for frequency control. Appropriate regulatory mechanism needs to be put in place for this purpose.POSOCO should take up the matter with CERC

POSOCO

9.3 Immediate All STUs should immediately enable under frequencyand df/dt based load shedding schemes. Central Commission should explore ways and means for implementation of various regulations issued under theElectricity Act, 2003. Any violation of these regulations can prove to be costly as has been the case this time.RPCs need to take up the matter for compliance. In case non-compliance persists, POSOCO should approach Central Commission.

STUs, RPCs, POSOCORevised UFR and df/dt scheme implemented by all utilities. In case of WR getting isolated from rest of NEW grid to arrest high frequency operation and unplanned unit tripping few units have been identified for planned tripping at 51.5 Hz.

9.4 3 months All out efforts should be made to implement provisionsof IEGC with regard to governor action. Central Commission needs to look into ways and means to hasten implementation of provisions of IEGC including that on governor action. POSOCO need to take up thematter with Central Commission.

POSOCO191-No. of units eligible for RGMO 73- No. of units confirmed 13- No. of units exemption applied 109- No. of units in various utilities are yet to be made to participate in the RGMO Exemption not granted to any generator by CERC.

9.5.1 1 month POSOCO should take up with Central Commission theissue of inconsistency between Congestion regulation and the detailed procedure framed there under so thatcongestion due to forced outages and UnscheduledInterchange (UI) can be handled effectively

POSOCO

9.5.2 6 months NLDC and each RLDC should have one real-timesecurity desk in all the shifts to be manned by engineer capable of carrying out TTC calculations. To facilitatethis, manpower at NLDC and RLDCs need to beenhanced with regulatory support to take care of financial aspects. Till this arrangement can be firmed up, various scenarios of outages could be built, which then can be used by despatcher in real time. Faster algorithm for calculation of TTC may be adopted by the load despatchers to update it in real time under outage

conditions.

POSOCO

9.6 Immediate Outage planning of inter-State and inter-regionaltransmission elements should be carried out in a coordinated manner at RPC fora (say Operation Co- ordination sub-committee of RPCs) in accordance with regulation 5 of Central Electricity Authority (Grid Standards) Regulation, 2010 and Section 5.7.1 of Indian Electricity Grid Code. In case need for emergency maintenance arises in between two meeting of Operation Co-ordination sub-committee, NLDC and RLDCs should allow such maintenance after carefully looking at prevailing system conditions under intimation to RPC

Secretariat

RPCs Already discussed and agreed in OCC of WRPC. 1. Interstate lines are coordinated by RPC/RLDC in monthly OCCs 2. Interregional lines are coordinated by NLDC in consultation with RPCs/RLDCs This is implemented and being regularly monitored in OCCs of WRPC.

9.7 6 months In order to avoid frequent outages/opening of lines underover voltages and also providing voltage support under steady state and dynamic conditions, installation of adequate static and dynamic reactive power compensators should be planned.

CEA, CTU, STUs10+17 reactors in various locations planned in WR and under various stages of implementation by PGCIL/GETCO/MSETCL. In 35th SCM, SATCOM which is modern technique for compensation of reactive power approved at six locations in WR.

9.8 6 months The powers of Load Despatch Centres and Regulatory Commissions related to non-compliance of statutory/regulatory provisions including that for non- compliance of directions and non-payment of UI charges, need review. Appropriate amendments need to be carried out in the Electricity Act, 2003 after such review.

Ministry of Power, Govt. of India

9.9.1 Immediate The regulatory provisions regarding absorption ofreactive power by generating units needs to be implemented

POSOCO

9.9.2 6 months An audit of devices such as HVDC, TCSC, SVC andPSS should be done immediately to ensure that their stability features are enabled. Further, exercise of PSStuning should be planned and implemented. Settings of these dynamic stabilizing devices should be reviewed atappropriate intervals

CTU, STUs, Generators23 generators PSS tuning completed. Telemetry data from TCSC/FSC not available to RLDC.

9.9.3 Immediate Functioning of existing PMUs and availability of theiroutput to RLDCs and accuracy of time synchronization should be monitored on daily basis and, if required, corrective actions should be taken on priority basis

CTU, POSOCOAll PMUs are working. Time synchronization issue.

9.10.1 1 year The synchrophasor based WAMS employing PMUsoffer a wide applications for real time monitoring andcontrol of the system, specially under the dynamic conditions. Adequate number of PMUs should be installed to improve the visibility and real time monitoring of the system. Further the applications related to the synchrophasor based wide area monitoring, protection and control should be embedded in the system

CTU PMUs on pilot project installed at Raipur, Bhadravati, Jabalpur, Itarsi. PMUs at KSTPS, VSTPS and SSTPS is planned to be installed by WRLDC as discussed in the meeting held on 21.09.12 to discuss occurrence at Sipat on 14.09.12. URTDSM is being implemented by CEA.

9.10.2 1 year Possibility of voltage collapse prediction, sensing globalpower system conditions derived from local measurements may be explored

RPCs A-eberle Relay installed at 400 kV Boisar (PG) s/s. In 110th PCM proposed at Jetpur, Bhilai, Aurangabad, Indore and Ponda s/s

9.11 6 months In order to assess the system security in real time andassess the vulnerability condition of the system, dynamic security assessment need to be periodically carried out at the control centers. A proper review and upgradation of the state estimation procedure is required to improve the visibility and situational awareness of the system

POSOCO

9.12 Efforts should be made to design islanding scheme basedon frequency sensing relays so that in case of imminent grid failure, electrical islands can be formed. These electrical islands can not only help in maintaining supply to essential services but would also help in fasterrestoration of grid

CEA, RPCs, POWERGRID, STUs, SLDCs andGenerators 1.Mumbai, Ahmedabad , GTPS uran islanding schemes functional at present 2. Scheme for Bhopal city/ Bina Traction/JP Bina Power stn is under development. 3. All CPPs are planned for islanding at a lower frequency

than 48.8 hz i.e. final stage of UFR setting so that these stations are available for startup power.

4. APL-SPS, LANCO-SPS is already there. SPS for Agra- Gwalior, Zerda-Kankroli, Badod-Modak is planned. Units to be backed down in WR have been identified.

9.13.1 1 year As National Grid is on the horizon, homogenization of Govt. of India, State Govts system operation philosophy is need of the hour. The present organizational set up of Load Despatch Centres need to be reviewed. System operation needs to be entrusted to Independent System Operator (ISO). In addition, SLDCs should be reinforced and ring fenced

for ensuring functional autonomy

9.13.2 3 months Training and certification of system operators need to be Govt. of India, State Govts given focused attention. Sufficient financial incentives need to be given to certified system operators so that

system operation gets recognized as specialized activity

9.14 2 years Intra-State transmission system needs to be planned andstrengthened in a better way to avoid problems of frequent congestion

STUs

9.15.1 6 months Appropriate amendments should be carried out in Grid CEA Connectivity Standards to restrain connectivity of a generating station or a transmission element without

required communication and telemetry facilities.

9.15.2 1 year The Communication network should be strengthened byputting fibre optic communication system. Further, theCommunication network should be maintained properly to ensure reliability of data at Load Despatch Cenres

CTU and STUs Approvals by WRPC

• Addl. 2672 Kms of OPGW, 14kms of OFC along with wideband communication equipment of adequate capacity for setting up of back-up SLDC at Govindpura, Bhopal, connectivity of Sub-LDC Gandhinagar and Sub-LDC Jetpur to SLDC Vadodara (Gotri) on OFC with suitable end equipments.

• Existing communication equipments (SDH 37nos. & PDH 72nos.) to be replaced at the cost of 3.89 crores

• Installation of PABX System at SLDCs of Western Regions, WRLDC and NLDC

9.15.3 3 months RTUs and communication equipments should have CTU and STUs uninterrupted power supply with proper battery backup so that in case of total power failure, supervisory control and data acquisition channels do not fail 9.15.4 6 months In case of existing generating stations or transmission RPCs, POSOCO

elements without telemetry facility, the same should be New stations are mandated for data transmission through put in place at the earliest. If prolonged operation telemetry before commissioning. without telemetry continues, POSOCO should approach Central Commission 9.16 1 year Large variations are observed in time taken for initiation

of unit start up (Boiler light up) by the stations afteravailability of start-up power and also for start ups/light up of subsequent units. While subsequent start-ups were very fast (10-20 minutes) in some of the units, in other cases they took considerably longer time – several hours. Reasons for the delays in attempting first start-up andsubsequent start-ups may be examined by the utilities in consultation with CEA. A standard procedure for preparatory activities and sequence of start up may beput in place by the stations to restore units as early aspossible particularly in contingencies.

CEA, Generating Utilities and RLDCs

9.17 3 months At inter-State level, the entire landscape has changed CEA over past few years. With de-licensing of generation and provision of open access in Electricity Act, 2003 and development of organized electricity markets, lot of generation is coming in the form of merchant generation. Four out of the five regions have been integrated and formation of National Grid is on the horizon. Under such scenario, there is need review the Transmission Planning criteria. 9.18 1 year There is need to reinforce system study groups in power

sector organisations to analyse the system behaviour under different network status/ tripping of lines/outageof generators. Where these do not exist, these should be created

CEA, CTU and STU

9.19 1 month It was felt that a separate task force may be formed,involving experts from academics, power utilities and system operators, to carry out a detailed analysis of the present grid conditions and anticipated scenarios which might lead to any such disturbances in future. The committee may identify medium and long term corrective measures as well as technological solutions to improve the health of the grid

MOP, CEA

9.20 1 year For smooth operation of grid systems, it is absolutelyimportant that all the power generating and distributing stations are connected on a very reliable telecom network. (i) A proper network may be built up preferably using MPLS(multy protocol label switching) which is simple, cost effective and reliable. In remote place where connectivity is a problem, the stations can use dedicated fibre cable from the nearest node (ii) Since POWERGRID has its own fibre optic cables, practically covering all major nodes and power stations, a proper communication/IT network may be built using dedicated fibres to avoid any cyber attach on the power system.

CTUs, STUs

Page 1 of 2

`Annexure-5 Automatic Demand Side Management

Draft scheme for Automatic Demand Side Management (ADSM):

As per Regulation 5.4.2 of IEGC, DISCOMs have to regulate their load at frequency

below 49.7 Hz under overdrawl situation.

The present schedule and drawl computation is available at SLDC / ALDC SCADA. The

same has to be extended to DISCOMs’ ADSM Master Control Station. Or otherwise,

the same can be referred from SLDC web site. DISCOM has to identify various

locations for tripping as per ADSM. As the phenomenon of frequency touching 49.7 Hz,

is likely to occur many times a day, the load on the feeders to be shed should be

rotated to minimize repeated occurrence on the same feeder. This can be achieved by

suitable Programmable Logic Controller (PLC). Further details can be worked out

based on number of locations for PLCs identified by DISCOMs, quantity of load to be

shed by DISCOMs etc.

Preparedness required from DISCOMs:

Identification of location for ADSM Master Control Station

Identification of locations for PLCs

Identification of feeders for load shedding

Page 2 of 2

Master Control Station

Field PLC

Field PLC

Field PLC

Field PLC

Field PLC

Field PLC

Field PLC

Field PLC

Field PLC

Field PLC

Field PLC

Field PLC

Master Control Station of each DISCOM will decide quantum of load to be shed based on UI value and will send signal to field PLC on rotational basis.

Master Control Station will recheck UI after every two minutes and fine tune till UI is made near to zero or frequency improves whichever is earlier. On frequency improvement, it will gradually restore the load.

PLC

UI input

Frequency

I/P from

Master Control Station

1 2 3 . . . 10

11 kV Feeders to be covered under ADSM

Feeders shall be rotated for tripping after every occurrence. Only a few feeders shall be operated at a time.

Documents

116 PCM MINUTES MAIL LIST - wrpcwrpc.gov.in/pcm/116pcm_minute.pdfAt 00:05 Hrs, due to operation of LBB protection of Bus-III at Korba Generating station, all the elements connected